don't know if this really counts, but a band mate recently got me into an Italian band called Goblin who did the music for a lot of Dario Argento films such as Suspiria.

a lot of their stuff is really cheesy prog crap, but some of it is very dark, chilling, and macabre.

Blow-Up

Herbie Hancock with an assist from the Yardbirds.

The Nosferatu soundtrack by Popol Vuh

2001 soundtrack and A Clockwork Orange soundtrack

Thief soundtrack by Tangerine Dream

Any of the soundtracks for the Kubrick films.

That strange flute soundtrack on Altman's 3 Women

Most of the David Lynch stuff.

Most Howard Shore, specifically Cronenberg.

Early John Williams

Most Ennio Morricone

Most Nino Rota

Philip Glass score for Mishima

Toru Takemitsu

That recent Jonny Greenwood score, although derrivative, was still good for There Will Be Blood

all I can think of for now.

Jerry Goldsmith scores for Planet of the Apes and Alien.

Jerry Fielding, especially The Wild Bunch and Bring Me the Head of Alfredo Garcia.

That strange score for the Texas Chainsaw Massacre, which was done by Tobe Hooper and someone else.

Lift to the Scaffold

David Shire's score for The Conversation is fantastic. I was very chuffed to learn it had recently been reissued by a small San Francisco label Intrada:

http://www.aquariusrecords.org/bin/search.cgi

also

Dawn Of The Dead
most Morricone (particularly Once Upon A Time In The West, Once Upon A Time In America and Fistful Of Dynamite)
most of the Popul Vuh stuff for Herzog
Sorcerer
Assault On Precinct 13
Kes
Cannibal Holocaust

Pi
Fresh - I believe done by Stewart Copeland
Big Night

The Last Emperor

Psycho

Amelie

the Star Wars movies (the scores are probably one of the only redeeming qualities of Episodes 1-3)

The City of Lost Children (and probably a shit-ton of stuff by Angelo Badalamenti that I'm forgetting)