Synecdoche, New York
Suicide Circle
A Clockwork Orange
All Night Long (obscure japsploitation film, deserves a mention for the theme song alone)
Cannibal Holocaust
Pi, Requiem for a Dream, The Fountain, Moon
And some Morricone soundtracks.
Really? That's awesome. I liked it as well, but lots of people hated it, calling it intrusive and too embellished. I didn't find it intrusive at all, and in fact realized I couldn't remember having heard a single bit of music an hour into the movie.