What game do you think wove music most effectively into its gameplay, and why?

[GameOver22]

SnakeDrake said:
Demon's Souls I everytime you great into a boss fight epic music starts playing and it really gets your heart pumping. Hell even the music in the Nexsu is really good. Its clam and relaxing makes you feel really comfortable before your torment begins.

I agree with this. I never really recognized it before, but the boss music does integrate nicely into the game. I would also second what other people said about Shadow of the Colossus, particularly how the music kicks in with the bosses.