oh, and here I forgot one of those few modern composer who has a more classical approach and is not only accessible for atonal freaks like the mentioned schönberg: Arvo Pärt. truly magnificent, and I allways imagined many of his songs could be great as film music.
as done here, with Fratres for cello and Piano:
http://www.youtube.com/watch?v=5vO92REraUoMany will get repelled by the high religiousness and the choir, but I recommend you give it a try, some parts are really great, Te Deum:
http://www.youtube.com/watch?v=IBtYwGuLNG0much other great stuff from him out there.