Pretty much every Final Fantasy game has a superb soundtrack, but I’d have to say my favourites are FF Tactics, FF X, and FF IX. Shadow of the Colossus also has an excellent soundtrack. I liked Homeworld 2’s music as well.
Oh, man. Jet Set Radio Future (JSRF). Sometimes I kind of wonder why I like that game so much, since it’s actually pretty simplistic, but the tracks on there are really great. They’re sort of a mix of funk, rock, techno, and rap, and they’re really fun to move to.
The Concept of Love (JSRF Theme)
Fly Like a Butterfly
Count Latchula
Yeah, I would say FFX, and Kingdom hearts 1 and 2.
Mostly because I don’t know many video game soundtracks. 
I’ve been listening to a music CD from the game Crysis recently, at times the tracks get creepy, really like it.
I’m a sucker for anything Final Fantasy with a personal favorite being You’re Not Alone from 9.
Although I also find myself listening to Smash bros(melee, live, and brawl), Ace Combat 5, Tales of Symphonia and, does anyone remember Disgaea?
I have to say MOTHER 3, there’s so many tracks, and so much variety.
Cave Story has some good tracks too.
I dont know if anybody said it but Little Big Planet has best soundtrack
This.
YAY, someone reconises the greatness that is the MOTHER 3 soundtrack! 
Spyro the Dragon (the first game), with music written & composed by drummer for The Police Stewart Copeland. A truly classical score!
Jazz Jackrabbit 2 had some awesome music, definitely
The Silent Hill series have fantastic music (2 in particular), by the master Yamaoka Akira. The games wouldn’t be half as good without it, but I can listen to it just the same without playing, it’s that good. Some of the tracks can make me really, really scared, and that’s not common.
I also like American McGee’s Alice, by Chris Vrenna.
And yeah, JSRF is awesome too. I love Birthday Cake 
Diablo II - Tristram Theme
Played that game many times 
tie between The Legend of Zelda The Wind Waker and NiGHTS: Journey of Dreams.
I can play that song on guitar. So hard, but well worth the patience to learn.
I think the most amazing soundtracks are a tie between:
- Kingdom Hearts- Simple and Clean
- Shadow of the Collosus- Demise of the Ritual
- Final Fantasy 8- Liberi Fatali
- Final Fantasy 7- Aeris’ Theme [com](OMG!! HE didn’t pick One Winged Angel!!)[/com];p
If you have never heard Aeris’ Theme, HERE is a link.
Such an underrated song. 
Descent 2
World of warcraft
Aerith’s theme?!?! UNDERRATED!?!?!? gasps Where did you get that impression from!? From what I’ve heard Aeriths theme and To Zanarkand are the most loved out of all of Nobuo Uemastu’s work 
EDIT: Even though I’ve played it so many times… just clicked the link… and got all emotional all over again… sobs 
i think its Legend of Zelda a Link to the Past for super nintendo the music in that game is AMAZING.
I’m gonna have to say my favorite video game soundtrack is either Guilty Gear’s, TWEWY’s, or Jet Set’s soundtracks.