Your favorite eerie television themes/music

Rewatching some old episodes got me thinking about which shows had the best eerie/creepy/spooky music (either as the main theme or general incidental music). A good opening theme can chill you before the episode even starts! A good way to set the mood. Here are some notable ones I could think of (in no particular order):

Opening themes:

The Outer Limits - while I love the theme, I actually like the main background/end credits music more. Haunting. (it turns out I was thinking of the music in 'Valerie 23' - I seem to remember it being used more often throughout the series) ... the Control Voice helped too!
The X-Files - classic.
Unsolved Mysteries - bonus points for Robert Stack's gravitas.
Are You Afraid of the Dark? - nice imagery in the opening as well.
Buffy - just the first 5-10 seconds.
Babylon 5 - maybe.
Gargoyles
Batman (the slower parts)
The Tomorrow People - cheating a bit here since I've never actually watched this show

Incidental/background music only:

The Twilight Zone - although the theme is notable in its own right, I'm on the fence about classifying it as "eerie".
Tales from the Crypt (sometimes, depending on the episode) - again, the opening theme is nice, but a little too upbeat to qualify as eerie.
Lost (often overdid it)


So what do you think? What would you add/change on my list? What music/intro chills you the most?