The Age of Mythology soundtrack was even better than the game.
I gave away the game long ago but still have the Soundtrack CD that came with the Collector's Edition.
Edit: Oh, and Breakquest. The music is basically a bunch of recycled Maniacs of Noise MODs, but you can't really go wrong with that.

Right, so has anyone listened to Ere the World Crumbles?

Well, if we're talking about "epic" soundtracks, two of the best are
Halo
Severance - Blade of Darkness
Two of my best videogaming experiences ever....

I've already said that Shadow of the Colossus is the best, but Metal Gear Solid one is quite awesome too (probably the best thing in this overrated game)---> The Best is yet to come

There are many excellent soundtracks. Right now, I think of these:
The Ultimate Doom
Unreal Tournament (Mechanism Eight is awesome)
Duke Nukem 3D (some tracks are unforgettable)
Lost Eden's OST by Stéphane Picq
WipeOut's OST by Cold Storage
Quake 2's OST by Sonic Mayhem
The Nomad Soul/Omikron's OST with great songs from David Bowie's 'Hours'
Dreamfall's soundtrack, including very moving tracks and some excellent songs
Metal Gear Solid's OST by Harry Gregson Williams
Warcraft 1

I got a few soundtracks that I love
Alone in the Dark (2008) by Olivier Deriviere
Dune: Spice Opera by Stephane Picq
Prince of Persia (2008) by Stuart Chadwood and Inon Zur
Nights: Journey of Dreams
Betrayal at Krondor (CD version)
And my favorite of all
Xenogears by Yasunori Mitsuda.

@lowyhong
Yeah, I've listened to them. They are nice and smooth; indeed, a pleasure to listen to.

I knew instantly that I was about to play a stunning and unforgettable game when Wander rode out on the huge bridge leading to the massive shrine in the intro cutscene:
http://www.youtube.com/watch?v=y4UvBI9vADc
Shadow of the Colossus is beyond artistic, it's almost mystical.

The most "epic" soundtrack to me isn't from a PC game. It's from a Genesis game, one called Arcus Odyssey. Composed by Motoi Sakuraba.
It's amazing.
Speaking of soundtracks, please read this article I wrote about PC game soundtracks.

For me it'd have to be Tomb Raider, Planescape Torment or Rome Total War

Half Life 2 sountrack, I just love the Eastern European theme to it. You may not agree, but that's your problem.

One of the most overrated soundtracks in gaming history.

Well, I like it.

Nothing wrong with liking it. It's really good. It's just very, very overrated.

Meh, overrated for some. I found it just right. The hype surrounding the game really did make people wish it did more than it did.