Right now I'm mostly playing TF2, Minecraft, and a bunch of indie games. Part of that is because I can't play much other than source games. I might get back into Nullpo Mino (tetris clone) though, I used to pass a lot of time in boring classes with that game.
My GFX card is slowly dying, so I can't really push it as hard as I used to(it's underclocked right now). I'm going to pick up a GTX 670 when it finally goes, and then I'll work on replacing the rest of my computer as I can(switching from AMD to Intel) and going with upper midrange parts as I can afford them. After that, the list of titles I will be playing will expand. I've got no ETA on this though, as there are a lot of other things I must also attend to.