Castlevania, Zelda and Silent Hill (though I'd say all first 3) mentioned so I'm gonna say Alundra. Sure it's very Zelda/JRPG, but that game had some amazing music that just sticks with you.
Also a little tongue in cheek, but Adventures of Lolo. I'm not sure if there's just one song throughout the trilogy, but it sure feels like it. Weirdly it doesn't bother you. It's like a hypnosis that just makes you play one more level. One more try. Kind of like the Tetris soundtrack, but it never gets old.