Borderlands plays like a FPS version of Diablo. I don't normally like FPS games, but I did really enjoy that one. It is also really funny. I would absolutely recommend this.

Nothing like picking up a shotgun with an item description: "Holy Crap it shoots rockets!"

My 360 library is looking mighty thin, so I can't help you with much more than that. It is easily the game I have spent the most time playing on the xbox though.