Others would include:
Gundam osts (both 00 season had impressive soundtracks, and are the pretty much only thing I never disliked in them. Unicorn too, since it's pretty much made of eargasm)
Rebuild of Evangelion soundtrack. The original series wasn't bad, particularly the signature "Angel Attack".
And finally Needless. Some of the best rock (j-rock, but really, not only) you will *ever* hear in any anime. Yes it's that awesome.
Let's see the one's I listen to the most are Bleach, Fate Stay Night, Darker Than Black and probably Code Geass. As for my #1 I would have to say Fate Stay Night, has a nice mix of upbeat music and calm instrumentals.