I'm curious what you guys have to say about this. Are there any games you consider perfect? Can a game even be perfect?
My example of a perfect game is always Portal 1. Portal 2 has more going on, but in 1 there just isn't anything to shave off. From start to end, there is nothing I'd change about the game. It's short, infinitely replayable, great pacing. I like Portal 2 a lot in concept, in concept it should be a perfect sequel, but it just doesn't keep the extreme tightness of the original game.
I have two objections to Deus Ex being perfect. The stealth pistol is completely pointless. Enemies scream when they get shot with it, which will alert surrounding enemies. The only good use for it is distracting enemies by shooting a wall or something.
Also the footstep sounds are mixed too loud. Otherwise, perfect game. You're right.
Deus Ex came to mind as a good example of a game that is not perfect, but which is a towering achievement nonetheless. That might be a good follow-up thread :)