I love Elder Scrolls as much as the next guy, but... The Japanese have everyone else beat. They were the ones who made incredible scores to go with games. They practically created the RPG genre, including the epic soundtracks that they usually include. I'd say it's a tie between the Final Fantasy series and The Legend of Zelda series. Final Fantasy X had an incredible soundtrack (To Zanarkand is absolutely stunning), and I personally thought Wind Waker's entire soundtrack to be the crown jewel of the Zelda franchise.