The only soundtracks I own is the Zombie/Cannibal Ferox double disc (
Zombie and Cannibal Ferox Soundtrack (CD))
big fan of Alexander Schevchenko's work on Iskanov's films, the soundtracks on Nails and Visions Of Suffering are incredible.
Goblin (obviously), Fabio Frizzi - I have several soundtracks on MP3, would love to own more on original but some of them are really hard to find at reasonable price. I find some soundtracks help me concentrate (a lot of music distracts me too much when I'm trying to work).