Resident Evil 4 probably. It’s so calming, yet off-putting. Not super melodic, but still simple enough to remember. Great theme that offers the player a bit of respite, while still keeping the tension up.
Not sure if it counts as a save room (can't remember if you can save in there) Persona 2 the velvet room with "Gymnopodiea Number 1" playing in the background. Went crazy trying to get the name of the piece, not even mentioned in the manual or credits of the game.