Xenosaga OST (from all the games in the series)
Kara no Kyoukai OST (from all the movies in the series)
Valkyrie Profile 1 & 2 OST
Tales of the Abyss OST

And I don't know if it counts, but the music you can listen on the in-game radio in Fallout 3 and Fallout: New Vegas. What can I say, I love the oldies!