Fallout 3 - 10/10. I'm not going to lie, this game is depressing, especially at high difficulties. It really puts you into the setting in the fact that you can't find money, ammo, medicine etc unless you really go scrounging, and in the beginning, the badies really kick your ass. This is the first game in a while that affected me like this. Putting the game on a lower difficulty, however, snapped me out of it really quick.
I like the fact that the things you do have real consequences (i.e. just being a good guy gets you jumped by a group of thugs, or somebody might get murdered just because of what you said), and that walking around the Wasteland can actually make you feel endangered.
Though there's some things that annoy me (you can't sleep in an owned bed!11) that carried over from Oblivion, I'm still giving this high marks because it evoked an emotional response from me that really made me uneasy.
Yeah, I know I'm playing this late, but this is the first xbox 360 game I've bought in a year and a half or so.