Some good Half Life Mods:

-Field Intensity
-Poke 646 (and its sequel, Poke646 Vendetta)
-Brutal Half Life
-IpogeiHD
-Solitary Echoes
-Half-Payne

https://psteamproxy.yuanyoumao.com/account/registerkey

Lurking my profile? Here, have some TF2 enhancement mods:

-Improved Create Server Menu
https://gamebanana.com/mods/332109

-Mastercomfig
https://mastercomfig.com/

-TF2 Bot Overhaul
https://gamebanana.com/mods/37013

-Color Coded Sniper Charge
https://gamebanana.com/mods/345919

-Playlist buttons
https://gamebanana.com/mods/290300

Two Half-life challenges:
-Complete the game in hard but you always need to have your health above 90 (example: 89 health, you lose, restart the game)
-Same rules, but your only weapons are the glock and the crowbar