The Deus Ex series is not only lengthy and rich in gameplay, but also marks groundbreaking AI and graphics. This is ironic because the game now looks like poop. People wave their arms above their head when on fire and cower in the corner when scared. It looks silly now but when the game was first released, seeing a character blink and have its mouth move was crazy to witness.
One thing that should be pointed out in this Deus Ex review is the ingenious ability to handle things your own way. I do not just mean alternate paths, but the flexibility of the game engine itself. For example, you could upgrade your legs with an augmentation canister, then jump on a wall or the roof of a building so no one can reach you. Then you just shoot them to pieces with a machine gun or a rocket or something.
A game like Deus Ex has lots of longevity, especially the Game Of The Year Edition. It is basically the same thing as the regular edition except it has a patch pre-installed for online play. But you do not want to play this game online anyway. If you do, you will just get a sniper-round to the face within ten seconds, or get obliterated from a pile of LAMS (mines) on the top of a ladder.
Luckily, the Deus Ex game series has a series of cheats for the pc to let you handle any situation. Of course this takes all the fun out of the game, but there will always be lazy people, I guess. To use cheats, you have to edit a text file or something. But even if there was not an official way to use cheats, you could always use Cheat Engine. Just choose choose Deus Ex in the program and though some trial and error you can freeze your health or ammo to nonsensical amounts.
Be sure to buy it if you have the chance.