I saw this tread and wondered "Why the fuck haven't I started a tread about this yet?!"
Got a bit of a fun story about this game(s)- bought the second one long time ago, thought it looked cool and didn't know anything about games then, which means I didn't understand shit. it all ended with me laughing as hell as I tossed things on people... they got so mad, but couldn't do anything...
Wasn't fun after a while tho, so didn't play it for maybe a year (more or less, no idea really) and then I found it, played it and loved it...
Was months later walking trough a store, and found somethig with the name Deus Ex. "Wow, a second? Special Edition?" Then I realized it was the first... that what I'd been playing was the second. Bought it right away, and loved it even more...
The music is wonderfull - that is how the future sounds. The story is great, all the choises you get and the endings and the second... in the end of the second, in the cold area, the feeling is so wonderfull there - all the messages left, it all creates such an enviroment.
And yeah, it's my favorite game

Tho Bioshock is real close... I love Rapture.