I give you Rapture
I picked up Bioshock yesterday, and just played a little bit of it right now. Impressive. The story is, your plane crashed over the ocean, and you discover an elevator that takes you down to the bottom of the ocean where a huge city exists. And naturally, since this is a computer game, as soon as your elevator stops at the bottom, you witness some monster disemboweling someone through the foggy glass. And then the door opens, and you're on your own. Woot!
More to come later.