I didn't hear so much music in the 4th Silent Hill game though. There were only a couple of scenes with music. Although it sounded very atmospheric and powerful when they did have the music.
There was one part that realy freaked me out the first time I heard it. During the Building World 2nd Time, there's a part where some weird flute noise comes from out of nowhere.
Also the ghost noises when the apartment is haunted.
As I play through Half-Life 2, there are a lot of amazing pieces in there... All of a sudden in a certain area you'd start getting this awesome music, but then it's cut off all of a sudden. How disappointing.
Out of everything though? Thats a tough one... I'll have to think on this.
Final Fantasy, Fahreneit, Test Drive 5, Rome Total War... All the lucas arts game like monkey island , Morrowind, Duke Nukem and others i can't remember
Metal Gear Solid series, all Mega Mans (especially Mega Man X), all Final Fantasies... Myth II: Soulblighter (Greatest. Computer game. Ever.) also has unbelievably good music in the main menu and the victory screens.