When I was going through my grandfather's vinyl collection (mostly classical stuff) I found some albums by the Polish composer Penderecki
. I was intrigued by the album covers and the titles (The Devils of Loudun, Threnody to the Victims of Hiroshima) so I gave them a listen. That is some really creepy stuff. Creepy, as in it creeps under your skin and gives you an uneasy feeling.
Later on I found out his music was used in movies and TV-series, f.i. The Exorcist, The Shining and Twin Peaks.
Oh and I agree with Veggie Boy on Exuma. When I was a teenager, one night I smoked a bit too much of the green stuff when Exuma's first album was being played at a friend's house. It gave me a very, very bad trip.