Great game. It has amazing gameplay, but what really gets me into this game at least is the story. This game will show you a dystopian city and all its horrors, and it will also show you how desperate people can get.
games for me aren't truly great unless they tell a good story as well, and this may be the best story ever told by a video game. Spend a bit of time in Rapture and you won't regret it. Amazing fun and a game with the balls to call bullshit on Ayn Rand and right-wing economic theory. Awesome.