Stay away from the console versions of Deus Ex (of course, the same can almost be said about all multiplatform FPSs), but I think the Xbox only got the sequel (titled Invisible War) and not the first one.
The original PC version actually ran on a (heavily modified) version of the Unreal Engine 1, so any PC younger than about 10 years old can play it quite comfortably. The sequel wasn't received equally well, but that's expected when you're trying to follow up the sheer genius that was Deus Ex 1.
So in short: so yourself a huge favor and play Deus Ex. It's easily one of the best games ever made.
EDIT: while you're at it, make sure you also play System Shock II, the "spiritual predecessor" to Bioshock. While not as refined as Deus Ex, it does share a lot of similar game mechanics and was very atmospheric and extremely well-written.