Fable 2: It's addicting as heck. All I can do is think about it while I'm away, and when I'm home I can't stop playing it and already thinking about my next couple play throughs. In short, already one of if not my favorite 360 game out right next to Oblivion and Dead Rising. All in all it's a huge step up from the first one in every regard and I liked the first one a lot.
Dead Space would be in my top 10 360 games list.