I painstakingly hand recorded over 2700 lines of data - each and every weapon's (and shield's) stats AND the stats of each and every different infusion of each of those weapons (and shields) which COULD be infused! (I do not recommend repeating the feat) All of them at max upgrade level so as to facilitate apples-to-apples comparisons, while sitting at the hard cap of 99 in every stat (other than Endurance)

I finished the game with minimal cheating (mostly restoring lost runes) and farmed up all the dropped weapons and armor I could, then I went offline and cheated in all the ones I couldn't get due to bugs, limited number of Rememberances, mutually exclusive items, or simple user error (Dung Eater violated me)
Once I made sure I had EVERY item legitimately obtainable in the game, I cheated again to make them all max level AND max out the character attributes (the absolute max rune level is 713 btw) I only left Endurance at 40 for "weapon swings till 0 stamina" testing
However, this save is for testing purposes ONLY, I do not use it online and I'll restore my clean(er) save if I ever do go online again. Only hack games for the good, m'kay?! :-P

Why did I pick these values? Well 40 Endurance is right about the level of stamina most people would have, or so I figured. 99 isn't that much different than the last soft cap of 80, and people who call 80 the "hard cap" annoy me so I set all my other attributes to the real hard cap out of spite :-P

Why should you trust what I say over anyone else?
Because I always offer you access to the raw data for you to see for yourself.
Which is available here[www.dropbox.com] (This data was recorded with v1.03.2 of Elden Ring)
Since this information was hand recorded, there is always the possibility my finger slipped and eg entered a 45 instead of a 54 and I never noticed or something else like that. I do not believe I made any mistakes, but I am only human so if you find any errors just let me know and I'll re-check the weapon.
That said there are errors in this data on Fromsoft's side and not mine which I try to point out below. I'm sure Fromsoft will get around to fixing them... eventually...
And of course any patch always has the chance of changing something NOT MENTIONED in the patch notes >.>

DPH = Damage per Hit
DPS = Damage per Second
DPSb = Damage per Stamina Bar

DPH is easy; our attack power is a direct measure of this value, but DPS is not so easy. DPS requires careful measurement of the time variable - small measurement errors would result in widely varying results. Thus, I have to approximate DPS with DPSb - count the number of swings each weapon takes to fully deplete the stamina bar, then multiply that number of swings by the attack power of one swing. In this way we can control the variables for consistent results; I only used light attack spam (L1?) without any pauses for stamina to regen and from a consistent amount of stamina (40 Endurance worth) without any talismans or other status effects.

Still, there are benefits to one over the other; DPH vs DPS, and I want to make sure you understand the tradeoff in picking one to favor over the other.

DPH Pros:

• Bypasses Damage Negation: Each hit receives a flat damage reduction and then a percentage damage reduction based off the opponent's defenses; the percentage damage reduction will be the same regardless of how many hits you deliver your damage in... but that flat damage reduction? That sees multiple small hits lossing more of their damage than a single large hit would, this also penalizes split damage type weapons eg ones that do Fire AND Physical damage since then the damage negation is applied twice
  
• Weapon Arts and Criticals: Big single hits mean that bigger single hits are bigger too - higher DPH buffs things like weapon skills and parries

DPH Cons:

• Higher Stamina Consumption: A single swing will eat up more of your stamina bar meaning you can't swing as often and doing so could leave you wanting when you need to dodge or block
  
• Slower Status Effect Buildup: Slow swinging weapons often get more buildup per swing, but even so they will not buildup effects as quickly as faster swinging weapons will

Reverse these for high DPSb weapons; they have much lower stamina consumption rates allowing for more swings which in turn cause faster effect buildup, but they suffer from a higher damage negation penalty and lower weapon skill and critical numbers.

So... which is better to focus on?
A: It depends. I think DPSb is generally a better measure of a weapon's worth, but it is really up to personal preference. If you are parrying a lot or really like weapon skills, then maybe you should focus on DPH more. I keep spreadsheets for both in the raw data link, if you don't like the sorting I used for a given section in this guide - go check em out.

All status buildup below is measured from one full stamina bar at 40 Endurance

Blood Venomous Fang (2808 Blood, 2256 Deadly Poison buildup dual-wielded) - The base weapon keeps topping lists because it has the lowest stamina cost per swing resulting in a whooping 20 swings till 0 stamina at 40 Endurance. Only Raptor Talons can match it for efficiency, unfortunately for them this one is just flat out better. With a multiplier like that, at least by the numbers, this is the single largest bleed buildup per stamina you can get, plus you get poison at no extra cost!

Blood Rapier + Blood Antspur Rapier (3510 Blood, 600 Rot buildup) - The Rapier gives you 130% critical damage while the Antspur builds rot and w/e else you feel like infusing it with (just not Cold, that combo is bugged, but lets be honest it's blood for both these weapons isn't it?) Not for scrubs like me who never learned how to parry, if you are going to powerstance something this seems like a good combo to me (UPDATE! I had only tested these as individual weapons previously, but when dual-wielded - rapiers manage to get in 30 pokes per stamina bar! Making them the new reigning champ for blood buildup!)

Rivers of Blood + Cold Uchigatana/Nagakiba (702 Blood, 630 Frost buildup) - The weapon skill of the Rivers of Blood katana is going to get nerfed, but even so this combo allows you to build frost with the off-hand and then reset it with the fire damage from the main-hand giving you two sources of damage bloom - Frost AND Blood (fire damage does NOT negate frost buildup, only the final proc'd effect which would normally give a -20% damage resistance debuff and block further frost buildup. Also, Uchigatana has better damage numbers but shorter range than the Nagakiba)
NOTE! Blood buildup only sees gains on weapons with Arcane scaling, thus the following weapons DO NOT benefit from Arcane investment; aka they'd have the same blood buildup with 10 Arcane as with 99
Other Weapon Types with this same strategy:
Axe: Fire/Flame Art + Cold Forked Hatchet (945, 1155)
Claw: Cold + Fire/Flame Art Raptor Talons (1245, 1365, Cold is better on the right hand here)
Curved Sword: Fire/Flame Art + Cold Scavenger's Curved Sword (498, 630)
Dagger: Fire/Flame Art + Cold Bloodstained Dagger (760, 1155) / Wakizashi (532, 735)
Flail: Fire/Flame Art + Cold Nightrider Flail (520, 635)
Great Hammer: Fire/Flame Art + Cold Great Stars (525, 635)
Greataxe: Fire/Flame Art + Cold Great Omenkiller Cleaver (525, 635)
Greatsword: Fire/Flame Art + Cold Flamberge (525, 635)
Halberd: Fire/Flame Art + Cold Vulgar Militia Saw (525, 635)
Hammer: Fire/Flame Art + Cold Spiked Club (615, 735)
Reaper: Fire/Flame Art + Cold Grave Scythe (525, 635)
Spear: Inquisitor's Girandole + Cold Spiked Spear (475, 525)
Whip: Fire/Flame Art + Cold Hoslow's Petal Whip (625, 735)
NOTE: Instead of Fire/Flame Art you could instead use one of the infusions which still allows buffs (heavy, quality or keen) and then use eg the Bloodflame Blade incantation

Great Stars - Heals you (or your mimic) on every hit, innate bleed buildup, and you can choose to either Cold infuse it OR keep it buffable to give it eg Bloodflame with Heavy/Keen/Quality

Godslayer's Greatsword - Surprisingly good stamina efficiency for a colossal weapon, it also swings like a weapon a size-class smaller than it is. This allows it to get really good damage numbers both in DPH and DPSb and since it is a colossal weapon most of its 2-hand attacks *ought* to be unparryable. Only downside is there is no way to give it bleed buildup

Zamor Curved Sword - Has a unique moveset which allows you to regen stamina WHILE attacking, and gives you access to frost buildup without needing to worry about a split damage penalty nor INT investment. Takes some getting used to since it is unique, but might also catch others off guard in pvp, unfortunately powerstancing it makes it lose the unique moveset - poop

Cipher Pata OR Coded Sword - The only weapons currently which do pure non-physical damage, they also get shield bypassing attacks. Downside is they do VERY little if any staggering

Lion Greatbow - Rivaling the Jar Cannon when used with Radahn's Spear Greatarrows, this "hidden" launcher - ammo interaction could be the hardest hitting ranged non-magical option in game. Only thing the Jar Cannon has over this combo is that its hitting like a truck the moment you can equip it but has ZERO attribute scaling

Blood Fingerprint Stone Shield - Bleed and madness buildup... who even needs a weapon?! Yes, this is a tad bit ridiculous, but people have done this before - wielded nothing but a giant shield and just smashed people into red goo with it. If it works like in previous games, you get constant blocking protection even while "attacking" with it and the only limiting factor is how long your stamina can hold out, you are going to need a LOT of Endurance... (unfortunately Madness only works in PvP and against NPC invaders)

Heavy REMOVES DEX scaling

* = NOT buffable; everything else IS

* = NOT buffable; everything else IS

ALL of these are buffable

* = buffable

Honorable Mention:
Blasphemous Blade restores 6.5% HP upon defeating an enemy

* = buffable

Occult buffs innate bleed and poison buildup

Some weapons gain more AP from infusion than others.
Here are the top performers as compared to the same weapon without infusion.
aka these are the weapons that REALLY do not want to be left as standard
If you want to see more, check the spreadsheet

Strength

• Heavy
  +76 - Heavy Giant-Crusher+25
  +63 - Beastman's Heavy Cleaver+25
  +61 - Heavy Brick Hammer+25
  +59 - Heavy Warped Axe+25
  +58 - Heavy Great Mace+25
  +56 - Heavy Club+25
  +55 - Heavy Large Club+25
  +50 - Heavy Nightrider Glaive+25
  +47 - Gargoyle's Heavy Halberd+25
  +46 - Gargoyle's Heavy Great Axe+25
  +46 - Watchdog's Heavy Greatsword+25
  
  
• Fire
  +160 - Fire Giant-Crusher+25
  +154 - Beastman's Fire Cleaver+25
  +135 - Watchdog's Fire Greatsword+25
  +131 - Fire Brick Hammer+25
  +126 - Fire Great Mace+25
  +126 - Gargoyle's Fire Greatsword+25
  +120 - Fire Large Club+25
  +110 - Prelate's Fire Inferno Crozier+25
  +109 - Fire Nightrider Glaive+25
  +106 - Guardian's Fire Swordspear+25

Dexterity

• Keen
  +137 - Guardian's Keen Swordspear+25
  +97 - Keen Urumi+25
  +77 - Gargoyle's Keen Greatsword+25
  +76 - Keen Giant-Crusher+25
  +72 - Gargoyle's Keen Great Axe+25
  +71 - Keen Brick Hammer+25
  +65 - Keen Warped Axe+25
  +61 - Watchdog's Keen Greatsword+25
  +57 - Keen Great Knife+25
  +55 - Gargoyle's Keen Twinblade+25
  +55 - Keen Vulgar Militia Shotel+25
  
  
• Lightning
  +160 - Lightning Giant-Crusher+25
  +154 - Beastman's Lightning Cleaver+25
  +135 - Watchdog's Lightning Greatsword+25
  +132 - Lightning Warped Axe+25
  +126 - Gargoyle's Lightning Greatsword+25
  +126 - Lightning Great Mace+25
  +125 - Prelate's Lightning Inferno Crozier+25
  +123 - Lightning Brick Hammer+25
  +120 - Lightning Large Club+25
  +109 - Lightning Nightrider Glaive+25

Intelligence

• Magic
  +184 - Magic Giant-Crusher+25
  +169 - Watchdog's Magic Greatsword+25
  +161 - Magic Brick Hammer+25
  +159 - Beastman's Magic Cleaver+25
  +155 - Prelate's Magic Inferno Crozier+25
  +141 - Gargoyle's Magic Greatsword+25
  +133 - Magic Large Club+25
  +132 - Magic Great Mace+25
  +129 - Magic Club+25
  +128 - Magic Warped Axe+25
  
  
• Cold
  +158 - Banished Knight's Cold Halberd+25
  +155 - Cold Giant-Crusher+25
  +155 - Cold Lance+25
  +148 - Cold Greataxe+25
  +145 - Cold Brick Hammer+25
  +143 - Monk's Cold Flameblade+25
  +142 - Troll's Golden Cold Sword+25
  +140 - Cold Curved Great Club+25
  +139 - Prelate's Cold Inferno Crozier+25
  +138 - Cold Glaive+25
  +138 - Cold Mace+25
  +138 - Watchdog's Cold Greatsword+25

Faith

• Sacred / Flame Art
  +205 - Sacred/Flame Art Erdsteel Dagger+25
  +183 - Sacred/Flame Art Giant-Crusher+25
  +162 - Sacred/Flame Art Brick Hammer+25
  +162 - Watchdog's Sacred/Flame Art Greatsword+25
  +155 - Beastman's Sacred/Flame Art Cleaver+25
  +143 - Gargoyle's Sacred/Flame Art Greatsword+25
  +142 - Prelate's Sacred/Flame Art Inferno Crozier+25
  +136 - Sacred/Flame Art Vulgar Militia Shotel+25
  +135 - Sacred/Flame Art Nightrider Glaive+25
  +131 - Sacred/Flame Art Club+25
  +131 - Sacred/Flame Art Great Mace+25

Strength & Dexterity

• Quality
  +163 - Quality Giant-Crusher+25
  +137 - Quality Brick Hammer+25
  +129 - Beastman's Quality Cleaver+25
  +126 - Quality Warped Axe+25
  +126 - Watchdog's Quality Greatsword+25
  +123 - Quality Large Club+25
  +122 - Quality Nightrider Glaive+25
  +121 - Quality Great Mace+25
  +117 - Gargoyle's Quality Halberd+25
  +117 - Quality Club+25
  
  
• Blood / Poison
  +88 - Blood/Poison Duelist Greataxe+25
  +88 - Blood/Poison Rotten Greataxe+25
  +82 - Blood/Poison Giant-Crusher+25
  +82 - Golem's Blood/Poison Halberd+25
  +82 - Prelate's Blood/Poison Inferno Crozier+25
  +81 - Troll's Golden Blood/Poison Sword+25
  +79 - Executioner's Blood/Poison Greataxe+25
  +78 - Blood/Poison Greataxe+25
  +74 - Blood/Poison Battle Hammer+25
  +74 - Blood/Poison Curved Great Club+25
  +74 - Blood/Poison Iron Greatsword+25

Arcane

• Occult
  +237 - Occult Giant-Crusher+25
  +210 - Occult Brick Hammer+25
  +203 - Prelate's Occult Inferno Crozier+25
  +178 - Occult Great Mace+25
  +174 - Occult Warped Axe+25
  +162 - Occult Large Club+25
  +145 - Occult Club+25
  +108 - Gargoyle's Occult Greatsword+25
  +84 - Occult Raptor Talons+25
  +73 - Watchdog's Occult Greatsword+25

Honorable Mentions:
Celebrant's Sickle - Grants 10 runes on landing attacks
Celebrant's Cleaver - Grants 10 runes upon landing attacks
Celebrant's Skull - Grants 20 runes on landing attacks
Celebrant's Rib-Rake - Grants 10 runes upon landing attacks

Cinquedea - Raises potency of Bestial Incantations by 10%
Highland Axe - Roars are enhanced by 7.5%

Sword of Milos - Restores 5 FP upon defeating an enemy
Sacrificial Axe - 4 FP restored upon slaying a foe

Blasphemous Blade - 6.5% HP is restored upon defeating an enemy
Serpent-God's Curved Sword - Restores 5% HP upon slaying an enemy
Greathorn Hammer - 3% HP restored upon defeating an enemy

Butchering Knife - Restores 1% HP when striking an enemy
Great Stars - Restores 1% HP on landing attacks

Pest's Glaive - +2% Non-physical Damage Negation

* = buffable

Honorable Mention:
Highland Axe enhances roars by 7.5%

These are just the top performers. for more results check the spreadsheet
* = buffable
Blood on an innate bleed weapon does not give more buildup than Blood on any other weapon
Blood on an innate poison weapon DOES buff the poison buildup

Honorable Mentions:
Grave Scythe gives +35 Vitality
Great Stars restores 1% HP on landing attacks
Sword of Milos restores 5 FP upon defeating an enemy

These are just the top performers. for more results check the spreadsheet
Cold usually REDUCES innate blood and poison buildup... just not on daggers
And then there is the bug afflicted Cold Greathorn Hammer
https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=2789153841

Blood and Poison actually buff the Fingerprint Stone Shield's Madness buildup... but not Occult
Unfortunately Madness only works in PvP and against NPC invaders
https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=2797086835

These are just the top performers. for more results check the spreadsheet
Poison on an innate bleed weapon DOES buff the blood buildup... but still might not be worth it

* = buffable
Blood, Poison, and Occult REDUCE rot buildup on the Antspur Rapier... but not the others... other than the bug afflicted Blood Rotten Greataxe
https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=2789168065
Likewise; Cold does not reduce rot buildup unlike its behavior with blood... except for the bug afflicted Cold Antspur Rapier
https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=2788474671

Sorted by Damage per Hit since ammo isn't unlimited
Ammo damage IS included in the listed attack power
∞ Damage per Stamina Bar = you can never run out of stamina from shooting alone

Honorable Mentions:
Lion Greatbow Radahn's Spears grant this weapon ~200 bonus damage (NOT included in the table)
Serpent Bow gives bonus Poison build-up to arrows

The highlighter was intended to draw attention to where an equal number of levelups were allocated between single-stat catalysts and dual-stat catalysts eg spending 20 points on one attribute could boost it to 30 while spending the same amount on two would leave them both at 20. This is exact for a Wretch, but only approximate for any other class.

However, the orange highlighter just happens to be the last soft cap for most of these catalysts.
The exceptions being:
Frenzied Flame Seal is also 30/45 but since it scales off of 4 attributes it requires quadruple the investment, if you want to use it - probably best to only go for the 30
Prince of Death's Staff despite being a dual-stat catalyst soft caps at 60/80
Demi-Human Queen's Staff actually soft caps at 20/40

Honorable Mentions:
Digger's Staff[eldenring.wiki.fextralife.com] boosts Stonedigger Sorcery by 20%
Azur's Glintstone Staff[eldenring.wiki.fextralife.com] reduces casting time of all sorceries by ~8%, but consumes ~20% additional FP
Lusat's Glintstone Staff[eldenring.wiki.fextralife.com] consumes 50% additional FP
Carian Glintstone Staff[eldenring.wiki.fextralife.com] boosts Carian Sword Sorcery by 15%
Carian Glintblade Staff[eldenring.wiki.fextralife.com] boosts Glintblade Sorcery by 15%
Carian Regal Scepter[eldenring.wiki.fextralife.com] boosts Full Moon Sorcery by 10%(?)
Staff of Loss[eldenring.wiki.fextralife.com] boosts Invisibility Sorcery by 30%
Gelmir Glintstone Staff[eldenring.wiki.fextralife.com] boosts Lava Sorcery 15%
Crystal Staff[eldenring.wiki.fextralife.com] boosts Crystalian Sorcery by 10%(?)
Rotten Crystal Staff[eldenring.wiki.fextralife.com] boosts Crystalian Sorcery by 10%(?)
Meteorite Staff[eldenring.wiki.fextralife.com] boosts Gravity Sorcery by 30%
Staff of the Guilty[eldenring.wiki.fextralife.com] boosts Thorn Sorcery by 20%(?)
Prince of Death's Staff[eldenring.wiki.fextralife.com] boosts Death Sorcery by 10%(?)
Golden Order Seal[eldenring.wiki.fextralife.com] boosts Fundamentalist Incantations by 10%
Gravel Stone Seal[eldenring.wiki.fextralife.com] boosts Dragon Cult Incantations by 15%
Giant's Seal[eldenring.wiki.fextralife.com] boosts Giants' Flame Incantations by 20%
Godslayer's Seal[eldenring.wiki.fextralife.com] boosts Godslayer Incantations by 10%
Clawmark Seal[eldenring.wiki.fextralife.com] boosts Bestial Incantations by 10%
Frenzied Flame Seal[eldenring.wiki.fextralife.com] boosts Frenzied Flame Incantations by 20%
Dragon Communion Seal[eldenring.wiki.fextralife.com] boosts Dragon Communion Incantations by 15%

100% Physical Defense w/ highest Guard for lowest STR Requirement possible
aka everything else offers the same or less Guard but requires MORE Strength

Magic Resistance w/ Highest Resist for lowest STR Requirement possible

Fire Resistance w/ Highest Resist for lowest STR Requirement possible

Lightning Resistance w/ Highest Resist for lowest STR Requirement possible

Holy Resistance w/ Highest Resist for lowest STR Requirement possible
If you can block with it, it is a shield... don't question it

Honorable Mentions:
Eclipse Crest Greatshield gives +50 Immunity, +50 Robustness & +50 Focus
Icon Shield gives a passive regen of 3 HP/s
Great Turtle Shell boosts stamina recovery speed by 8%
Twinbird Kite Shield boosts attack and defense by 5% while below 20% HP
Spiralhorn Shield gives +50 Immunity, +50 Robustness & +50 Focus
Sentry's Torch reveals enemies that are normally invisible
Beast-Repellent Torch will keep Beast-type enemies passive

This section is not my own work, it was brought to my attention by 5chneemensch and credited to "Kikbow from Discord."

2nd Source
The data sets mostly agree with one another, it would just appear that this Reddit source was running at ~2x the frame rate of the 1st source

To visualize the disagreement between the two data sets:

NOTE: Whips and Flails are FULLY unparryable, but only some of a colossal weapon's 2H attacks are unparryable
* = buffable

vs Fallingstar Beast, Onyx Lord, & Alabaster Lord:

• Starscourge Greatsword, Fallingstar Beast Jaw, Onyx Lord's Greatsword, Alabaster Lord's Sword, Bastard's Stars, Meteoric Ore Blade, & Wing of Astel: +30%
  
• Radahn's Spear greatarrows: +20%

vs Undead:

• Holy Water Pots: +400%
  
• Sacred Order Pots: +90%
  
• Golden Epitaph: +30%
  
• Inseparable Sword & Golden Order Greatsword: +20%

vs Dragons, Magma Wyrms & Banished Knights (w/ only half vs Ancient Dragons):

• Dragon Greatclaw, Dragonclaw Shield, & Dragon King's Cragblade: +30%
  
• Bolt of Gransax, Icerind Hatchet, & Dragonscale Blade: +20%
  
• Dragon Halberd & Grafted Dragon: +10%

Source: Reddit User Elitegmr

Other Equipment with Special Effects:
Wiki Source[eldenring.wiki.fextralife.com]
Reddit Source

If you liked this guide, you might also like my other Elden Ring guides:
https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=2765060616
https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=2785301831
https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=2797241037

If you have any constructive criticism or helpful comments - I welcome such feedback.
Or if you have any questions I'll do my best to help out.
Otherwise thank you for taking a look at my guide. :)
And remember to rate and favorite this guide if you found it helpful :D