I quite liked the Chrono Cross soundtrack...other than that one I can't think of any that really stood out for me.

i think most videogames actually have pretty good music. it's usually the best thing about a game. the only thing is that it's designed to repeat and play in the background a lot of the time so not a lot of it is worth listening to more than a couple of times cos it gets boring and stale pretty quickly but still i put the vg soundtracks on my ipod and i listen to them when i'm walking around or at work sometimes.

usually there are only 5 or 6 out of 80 or so songs i like but that's still pretty good. i just put those ones on and delete the rest. the ones i've liked the most are probably EHHHHHHHHHHHH deus ex, killer7, final fantasy (just pretty much all of them have some good songs), breath of fire (3, 4 and DQ have some great songs especially DQ) uhhhhhhhh elder scrolls is all right in a cheesey way but i like cheesey just fine, silent hill when it isn't trying to be scary.

yeah there's lots more i've listened to outwith the game but i mean it's all the same kind of stuff apart from deus ex and killer7. i don't listen to it that much and actually i've tried to phase it out of my ipod cos since it's BG music it's easy to get into a habit of sticking it on shuffle and never listening to any real world music. it gets really stale quickly, too.

splinter cell: chaos theory.

i'd probably point to it as the single best creative accomplishment to ever come out of the entire history of vidiot games

Music makes or breaks a game for me. It doesn't really matter what type... it just has to work within the context of the game.

These are just a few that stuck out as I was in here.

Earthbound had the only music that means anything to me

and Metal Gear Solid 2 has some good jungle

Edit: I really need to hear Chaos Theory too - does it matter if I haven't played the game because Splinter Cell really doesn't interest me

I always liked the music in the Phoenix Wright series. It always seemed to fit with the whole LAW AND ORDER theme. I actually recently got my hands on the orchestrated soundtrack of the Ace Attorney series, it's pretty nice.

I also really liked the Starcraft soundtrack. The Terran theme kicks ass.

uhh and pokemon tends to have catchy music

I like most RPG soundtracks, but the ones that I like much more than the others are the Wild Arms soundtracks. Yeah, I really enjoy Michiko Naruke's music since she did most of it for the series. Just listening to the opening theme of the first WA is great.

Earthbound also had really good music. It really sets the mood of the game for you.

Favorite

PC game soundtrack: Descent II / Doom / Ultima Underworld II
NES: Mega Man 2 / Castlevania
SNES: Chrono Trigger / Secret of Mana
Genesis: Shining Force / Streets of Rage
Sega CD: Ecco the Dolphin CD
PSX: Metal Gear Solid
N64: Ocarina of Time
XBox: Halo

I'm a sucker for game music and I try to keep up with the good soundtracks as much as I can. I'll mention a couple here that I didn't see mentioned (I might not have been looking close enough) cos I agree with most of the others posted up:

Heroes of Might and Magic Series - Regardless of what you think of the games they have pretty fantastic music. I think my favourite soundtrack is from the third game but I like most of it. The heavy, driving drums mixed with the movie-like strings are really cool. In general the music is just of a very high quality and adds an air of prestige to the game.

Fallout Series - Ignoring that Fallout 2 has a very similar soundtrack to the first I think these are worth mentioning. Mark Morgan did wonderful things in the sense that these tracks are so ambient and sparse yet they still stick in your head and provide so much atmosphere. Perhaps not the best stuff for listening on its own, but in the game environment it's basically perfect. He's moved on to TV shows like One Tree Hill so I'm guessing he's not going to be taking part in the third Fallout which is a shame!

I may be alone but I think the FFIX soundtrack is probably one of the best achievements in Nobuo's catalogue.

Let's try top 5 video game soundtracks!

5. Chrono Trigger
While I'm not a huge fan of the game like everyone else seems to be, I absolutely love the music in Chrono Trigger. Especially Zeal's theme is awesome.

4. The Adventures of Alundra
Alundra is one of the lesser known action-RPGs, which also means it's music is not that well known. But it does kick serious ass! Check out "The Shrine of the Lake" for some awesomeness.

3. Donkey Kong Country
Donkey Kong Country not only had awesome gameplay and graphics, it also had superb music. I really liked the swimming level music: "Aquatic Ambience".

2. Terranigma
Terranigma was never released in the US so some of you might not have the pleasure of seeing and hearing this masterpiece. Lots and lots of great music in this one. The overworld theme is very very majestic!

1. Castlevania: Dracula X Chronicles
Castlevania games have had excellent music through out it's whole history. Even the crappy 3D games had excellent music. For some reason Castlevania always seems to be forgotten when it comes to video game music even though the games feature some of the best video game music ever. Out of all the Castlevania games Rondo of Blood has the best soundtrack of them of all. Recently it got remade for PSP as Dracula X Chronicles meaning the music also got quite a bit better in quality! Awesome. Dracula X Chronicles soundtrack has pretty much all essential Castlevania tracks minus Iron Blue Intention.

Divine Bloodlines

Vampire Killer

Bloody Tears

extra: Iron Blue Intention (Portrait of Ruin version. Also featured in the Mega Drive/Genesis title Bloodlines)

I love the Dragon Quest soundtracks though, especially when performed by a live orchestra (the London philharmonic has some great recordings).

The NES Mega Man games had pretty sweet music, too.  I don't know who wrote it though.

Final Fantasy games are of course a sure bet usually.

The Japanese-only PS2 game Moonlit Shadow had a really cool soundtrack.  Some of it was written by Yasunori Mitsuda (this is how I heard of it) but most of the good stuff was written by some guy named Miki Hagashino I think.  The music was either hardcore Jazz or some sort of urban hip-hop and it's just way too cool.

Also Romancing SaGa for PS2 had tons of ridiculously cool music.  I think it's too bad that it doesn't get much attention.

Aaaaaaaaaaand Unlimited SaGa for PS2 has amazing music.  It is one of the worst games I've ever played and for some reason none of the good tracks get played very often in the game so you'd never notice how amazing the music is, but the OST is a treat.

C&C 95 had some of the best video game music ever.

http://www.youtube.com/watch?v=H4uuVou6rG4&feature=related
http://www.youtube.com/watch?v=9qvKvV7sKoE&feature=related
http://www.youtube.com/watch?v=SFIT4gZUtb8&feature=related
http://www.youtube.com/watch?v=vj-jkRzFg4o&feature=related

Broken Sword series has great music written by Baritone Pheloung. He's the same guy who wrote the music for inspector morse. The music is not so thematic like many other video game music, but it has a unique timbre and colour to it that is very rare to hear in all manner of soundtracks

http://www.youtube.com/watch?v=3FOFc9RXICU

This is the closest I could do find to some of the music from the game. It's just the introduction movie, but has a lot of music in it