Some more favorites:

Legend of Dragoon: This soundtrack is underrated.
Chrono Cross: CT is best, but this one is awesome too.
Baldur's Gate II: It's epic. Even character creation is epic.
Xenosaga: Not the composer's best, but still damn good.
Kingdom Hearts: Despite how I feel about the series, the music goes well with all the environments and it totally works.
Morrowind: Skyrim and Oblivion have okay soundtracks, but constant feeling of being an outsider and not belonging is excellent with this soundtrack.
Arcanum: The music is just violin for a good deal and it's awesome.