Considering a few games, not pulled the trigger yet. Still have a few games I am really active in and a huge game backlog.

The Witcher 3: Wild Hunt GOTY. I don't usually get into third person hack and slash games but found this game to be excellent.
X2 The new threat. Slowly trying to complete this collection without having to buy the gold box edition.
Wallpaper Engine. Then made my first wallpaper using a recorded video from NASA and the SDO (Solar Dynamics Observatory).
https://www.youtube.com/watch?v=l3QQQu7QLoM

Well Steam sale is over but anyway I will recommend Planetary Annihilation, as at first sight game doesn't look something extraordinary but after some 2-3 hours of gameplay you get really addicted :)

Berserk, it is a great game! However, after playing a while, I tried multiplayer and was totally owned. I practiced some more, went back, got owned again. LOL. I stick with single player now. Haha!

Yes man same here Just went on a multi and was just thinking that I was very prepared wen there was raining with nukes on my planet it was crazy :D