Main theme from Robocop (1987). I loved that sound so much that I even put it on a ringtone.
You've got a great musical taste, by the way.
Well, now. I haven't actually concentrated on any music for years, but off the top of my head -
Air - Virgin Suicides
Damon Albarn - Ravenous
Cliff Martinez - Solaris
Donnie Darko (the score)
The End of the Affair - Michael Nyman (he's got a rep as a poncey musician, I know, but this is just beautiful).
Orbital - Event Horizon
Almost anything by James Horner - from Star Trek to Beautiful Mind.
Nick Cave / Warren Ellis - The Assassination of Jesse James.
Dawn of the Dead - NOT the terrible 'Goblin' soundtrack, but the score they actually used, released by Johnny Trunk in the 90's.
Oh, and like everyone else, I agree that Gladiator is the business. I hear that, and I've got to pretend I AM a gladiator.
Mine is Braveheart, Gladiator, Highlander Endgame, Willow, Conan the Barbarian, Terminator Judgement Day, Cast Away, The Last Of The Mohicans, Mummy&Mummy Returns, Tales From The Crypt, Once Upon Time in a West, Pet Semetary, O brother where art thou, Pirates of the Carribean.