CLANNAD or Dragonheart. CLANNAD would've been obvious because it's hours' worth of music and there's a lot of wonderful tracks I couldn't trade for the world, but Dragonheart has that sense of magical wonder that promises optimism and adventure even though the duration's less than an hour long.
Chrono Cross. A game whose superiority seems to have caused some controversy but with a sound track that has, if not everything i would ever WANT music for, everything i would need music for.
Just about every track in the game is on-point and conveys a strong sense of the events they back up. This game pushed the SNES to its absolute limits and succeeded.