This thread deserves a bump. I've been listening to a soundtrack compilation I made a few years ago, and man I love it. I will name specific soundtracks later, but for now I just want to mention the big names I love (and yes, I know they're popular and it's maybe too all-inclusive):

Danny Elfman

John Williams

Bernard Hermann

James Horner

James Newton Howard

Vangelis

Hans Zimmer

All fantastic composers, but I think Danny Elfman shines above the rest. The man can convey so much emotion through music. I especially love Edward Scissorhands. Practically brings me to sissy tears!