I've been listening to game remixes as my main source of music for a few years now (sprinkling in mainstream stuff for kicks). A good website is
OCRemix.orgIf you haven't been there, I suggest it. There's a lot of high-quality shit, regardless of what you're into. However, like mainstream music, there is also a high quantity of crap to sort through. Some guys though, they just make the Black Mages look like a school band.
Some of my favourite soundtracks, especially if we're talking about in-game musical experiences, has got to be Shadow of the Colossus, Gran Turismo 3 A-Spec (if that counts), Sonic Adventure 1, Grandia 1, Spyro the Dragon 1 (yep.), Chrono Cross, Xenogears, Crazy Taxi 1, and I'll toss in Sonic the Hedgehog 1,2,3/&Knuckles.
Why? Shadow of Colossus is a paragraph of why. That game, with bad music, would have been all the less fun. They really built up this feeling of supreme accomplishment, or intense danger, or sheer size through their tunes.
Gran Turismo 3, while hosting mainly 'mainstream' songs; I have to say of the series as a whole, 3 A-Spec was just top tier for their playlist. When you're forced to listen to 30 or so songs as you do relay races for countless hours, it really matters what songs are available. With GT3, there was never a song I'd skip, and it always felt especially grand when you're taking the final stretch of a lap, and 99 Red Balloons kicks in with the guitar. Golden.
Sonic Adventure 1, and all the other Sonics I mentioned for that matter, will forever be remembered for the fun, fast-paced tunes. Nothing like the continuous BRINBRINBRINBRINBRING of collecting gold hoops with a fun ditty in the background. On a similar note, this is why I like Crazy Taxi's soundtrack. So loud, fast, and energetic as you pulse through San Fran collecting quick money by racing against traffic... God I love that SEGA vibe!
Chrono Cross, Xenogears and Grandia, these three have the kind of soundtracks I could just listen to on their own. From Alternate Termina, to Broken Mirror... I just absolutely love these tracks.
Last but not least, Spyro the Dragon. While a lot of people don't like Spyro, myself now included after the purple bastard sold out, the original soundtrack just kind of rolled around in the background while I played. It neither stood out, nor fell behind, it was there in perfect harmony with the gameplay/level design. Oddly one of the few games I noticed this in.
Also, what's a Gam?