Haven't played any of the latest games (on a PIII + 810E! C'mon!), so my know-how regarding game-music stops @ Max Payne, and for the moment, that's the fav.
I liked the depth & strength (can't quite describe it properly) the sound had in the HL2 promo vids. So I guess in-game it must rock even harder!
So best sound FX award goes to HL2 (even tho I haven't played it)
Unreal had some pretty nice sound FX too (though I preferred watching those heads bounce and roll than listen to the noise the plasma gun made.
)
Not to forget the first GTA - considering the time it was made, the sound was probably revolutionary!
Deus Ex had 'adaptive' music, based on the environment and situation u were in. Don't know how good it's in Invisible War.