One of the things that drew me to BLEACH was that Kubo Tite gave his characters theme songs that I was familiar with. Idioteque for Ishida was my favorite followed closely by Wing Stock for Rukia and No Song Unheard for Chad. I'm curious about all the characters in BLEACH that have not been assigned theme songs.
I'd give Soi Fong You Oughtta Know by Alanis Morrisette, entirely for her whining during her fight with Yorouichi. And I toyed with giving Mayuri Smack my Bitch up by Prodigy on how he treats Nemu but that doesn't really work.
Anyone got any other ideas?