haunting/dark classical

I'm very fond of most of what's been recommended and applaud the others for their thoughtful responses. I would like to recommend a piece that won't qualify as Classical music in the usual sense but it is orchestral and most definitely describes what you're are looking for: the sound track of "The DaVinci Code." It's extremely dramatic and dark. The recording is wonderful, too, with unusually good dynamic range and low frequency reproduction.

Schubert's Unfinished Symphony #8 - Get the complete Symphonies box Frans Bruegen and the Age of Enlightment Symphony Orchestra. Mozart's final work - the Clarinet Concerto, he had alot of haunting/dark problems in his life when he wrote this work.

Haunting, dark,classical. Phillip Glass. Dracula, Low, and Heroes. Played by Kronos Quartet.

Tchaikovsky Symphony #6

A little late to this thread, but anyway --

All the above recommendations (good ones) come from the classical, romantic or modern periods, which are the areas first explored by new classical music listeners. After you get acclimated, consider dipping your toe into the baroque and renaissance periods, where vocal music is more common. From the baroque, Purcell's "Dido's Lament" from his short opera Dido and Aneas. From the renaissance, the madrigals of Carlo Gesualdo, whose dark and haunting life is reflected in his music.