I've probably only played about 10 in my life.. I love games but I rarely bring myself to buy new ones.

Oblivion is probably the best I've played. I've finally gotten sick of it through after finally realizing that almost all of the quests require you to do almost exactly the same thing with different stories and dialog.

But I've been playing Left 4 Dead 2, although it isn't the type of thing I'd normally like, I guess I like the online aspect and having a few friends online who I can play with. So that's currently the game that entertains me the most.