Dragonball Z
Ghost In The Shell (GITS, GITS 2.0, Innocence, Stand Alone Complex, SAC2) (Basically all of it).
Cowboy Beebop
Death Note
Ninja Scroll
Patlabor 1 & 2
Akira
Street Fighter II: The Animated Movie
Cyber City Oedo 808
Escaflowne
Bible Black
Princess Mononoke was cool too but I never got into that Spirited Away crap.
Blood: The Last
Vampire was pretty well animated for 2004 and blew me away, although wasn't that into the premise.
Many many more I'm sure but these are the ones that stick with me from the top of my head.
Yoko Kanno and Kenji Kawai are two of my fave Japanese composers
The symphonic Akira soundtrack kicks ass too.
Rory Gallagher did the UK sountrack to Cyber City and I really enjoyed the vibes I got from it in the early 90's.
Also Cory Lerios and John D'Andrea - I must firmly shake these guys' hands one day on an absolutely astounding American soundtrack to Street Fighter Animated Movie (also features KMFDM, Korn, Alice In Chains, Silverchair - some of my fave bands to date, all due to this idiotic computer game franchise).