Game suggestion for Steam Sale

I've just bought L4D2 lol
Since my pc can't stand much game like GTA V I would consider buying it later
Gmod I already have 1000h and learning to code for it
I don't really like CoD
And already have CS:GO too
My type of game I think is survival or puzzle like Portal
Thanks for all the suggestion guy ^w^
Wish you a happy new year (ik it's early)