The title is pretty self explanatory- what's your favorite music in anime?
My favorites are:
FLCL- kickass J-rock. Just fucking awesome. I have both OSTs and they're great (and the fact that rightstuf has them on sale for $6 each....yeah, go get them!)
Cowboy Bebop- obvious reasons
Fullmetal Alchemist- great openings and endings. Got me into L'arc en ciel, Asian Kung fu generation, and Porno Graffiti.
Death Note- Good openings and endings. Got me into Maximum the Hormone.
Inuyasha- crappy as the series may be, the openings and endings are pretty good and have a nice classic Japanese feel to them.