I recently played BIOSHOCK.
OH.
EM.
GEE.
It was a bit short for my taste, but this game hit me on a big level.
It. Is. Spectacular.
The plot, the characters, the environment, the choices... all amazing.
Plus, if you actually read into it, instead of just playing it through, it's touching in an odd sort of fashion. I won't give away plot points for those that haven't played it, but some of things the antagonists say really make you think, or wonder why you're actually doing some of the tasks you do, and I genuinely felt betrayed after learning how a character had been manipulating my character throughout the story.
I think Big Daddies are one of my all-time favorite characters in a video game ever.
They're the most noble creatures in the game, charged with protecting those little girls (or whatever you view them as) from those out there that would do them harm. I actually felt remorse when killing these fictional characters.
If you've played it, please, share your thoughts.
If you haven't, go do it. It's available for every system other than the Wii.