Happy Birthday Ross!
I know a couple games with great soundtracks.
One is Unreal Tournament 2004. The sound track to this game is amazing and has a lot of variety.
Unfortunately, there isn't really a place to get the soundtrack other than the game's files.
The second game is UBERMOSH. This game has a stellar high octane soundtrack.
http://store.steampowered.com/sub/66335/ ---Steamlink
I think it can only be purchased from Steam though.
Here's one of the songs I could find for a preview: