I like Aphex Twin's "Selected Amibient Works VII'. Volume one, though, is more techno, more boring. Orbital is good, so is Eno. Slowdrive is something to look at. They have a song on the 'Doom Generation' sndtrk, 'blue skied an' clear' that's pretty good with a gigantic, enveloping sound.
Best Ambient Music
Who's your favorite "Ambient" musicians. Patrick O'hearn is a favorite