Another vote for Deus Ex Human Revolution. The directors cut just came out so you can get it with some extra content.
I've recently got into Battlefield 4 and I'm having a blast with it. I hear alot of bitching about the game crashing and people having issues with it but none of that has affected me. Keep i in mind though if you're considering the game.
Borderlands 2 is pretty awesome and can be got for very cheap on steam. If you're looking for some multi-player co-op fun you really can't do much better.
Call of Duty Ghosts sucks. Avoid that turd at all costs.
Bio-Shock Infinite was pretty fun, if disappointing. It's pretty cheap now though and worth considering.