Best Game music(non big-label artists)
16-Bit Sonics. Chemical Plant Zone being my favorite.
FF7, Sephiroth's Choir(One Winged Angel) Hate the game, LOVE the music.
And call me crazy, but I loved the arranged beeping that KOF R2 for Neo Geo Pocket Color had. I even have the soundtrack on official CD... all beeping
Best Game music(W/ big-label artists)
Wipeout. Pick one. They all rock.(Haven't played the PS2 one yet...)
Project Gotham. It has SO MUCH music on it, you gotta like it. Resonate - Sir Mix-a-Lot, 19-2000 - Gorillaz, Call It What You Want - L.A. Symphony
Oh, and my favorite off of Overclocked is Ghosts'N Goblins - Instant OC ReMix.