A search didn't turn this up for me, so sorry if it is a repost, but;

I'd like to recommend the soundtrack for the game LIMBO. It has a nice spooky ambient feel and most of it is kind of quiet and creepy as oppose to loud and startling. I think you can listen to all of it here to try before you buy.

I also recommend the game. It's not likely everyone's cup of tea, but you can check out the reviews and make your own decision.