My vote is for Sega Genesis’s NHL 94. Every time I hear that jingle my hear reverts back to that of a school kid. As a testimate to the song’s greatness it was used in the movie Swingers.
I believe a bunch of big name alternative rock bands did the music for SSX Tricky and the Tony Hawk games.
I also like some of the music from Unreal Tournament, believe it or not.
Six tracks of it.
Frank Klepacki has done some awesome work for the Command and Conquer series. My all-time favorite is “Hell March” from Red Alert.
My favorite SSX song is “Song For Dot” by the Space Raiders.
I think one of the coolest soundtracks has to be Grand Theft Auto III. The amount of planning, time, and execution that went into creating all those radio stations is amazing. Does anyone know if real bands wrote/performed the songs or are they original? I know the Flashback FM channel is the Scarface soundtrack, but what about the others?
Metal Gear Solid 2 has cool music too, especially the Harry Gregson-Williams version of the theme song.
OH MY GOD, ITS THE MOTHERLOAD!
THANK YOU THANK YOU THANK YOU
No problem. 
I was enraptured when I first found this website. It took me back to a time when all I had to worry about was getting my homework in on time and trying to beat the next level of “Section Z” on my NES.