Deus Ex

The Good
Involving storyline. Excellent, challenging gameplay. A lot like SS2 in terms of gameplay, but the environment is much better. Offing corrupt bureaucrats hellbent on world domination (hopefully not too much of a spoiler) is much more gratifying than killing pseudo-zombies. You aren't some god character who can blast through areas Doom-style, a welcome change from the "realism" some games claim to have (Nam comes to mind). All the basic aspects of games are outstanding in Deus Ex.

The Bad
The game likes to hold your hand with periodic transmissions and datapads with top secret info left lying around in places that just make no sense. AI is pretty weak, better than a lot of games, but still enemies just do things that the game acts like they can handle but can't. Shooting an enemy and then taking cover causing them to not know where you are when they clearly should, for example.

The Bottom Line
Great meshing of FPS and RPG with an incredible and interesting storyline. Do not not play this game!