The most haunting music you ever heard?

Alison Krauss' "Jacobs Dream" off the CD "A Hundred Miles or More" should be added to the list. Haunting and heart wrenching.

I would second Leonard Cohen's "Hallelujah". I also have the remastered Jeff Buckley version, but Cohen's original on a top set up sounds so rich and holographic and the chorus sends a chill up my spine. I would also put Peter Gabriel's "Dont give up" in the same class, with Kate Bush singing the chorus.

Pet Cemetery was haunting. No soundtrack required.