"the backhorn"
Yikes, forgot all about them. Yamada Masashi's vocals are f'cking awesome. Since CASSHERN is coming to the US they'll probably get a few new fans here. They had the best song on that soundtrack even though its packed withalot of great songs. Requiem is just awesome though, especially the opening.
"Ryuuzetsuran just seems like a real mess of ideas."
It's much more experimental than their other albums, but I think it works. Some of their best songs are on it imo. Kanngae Goto (the one with vocs from Yuu and AKKO), Sennnichikou and Otona no Himitsu are all really top notch. I do agree though that Gyotaku is their best. C7 is still my favorite song by them.
"Listen to the new japanese stuff like Asian Kung-Fu Generation "
Check out Art-School. They sound alot like AKFG.
Some other good bands, The Brilliant Green (release a new album damnit!), Swinging Popsicle, advantage Lucy, Paris Match, Beret, Moi Dix Mois (if you want music that sounds like it was ripped out of CV) and Onmyouza. For singers/pop groups, Nakashima Mika, Fayray, Ringo Shiina (she's now formed Tokyo Jihen so her solo career is no more), Salyu (if you've seen All About Lily Chou-Chou, that's her singing the songs) and HALCALI. HALCALI is pop rap but its so good that you've gotta love it. Their videos are are the best.