Metallica. They stopped progressing a long time ago. There is only one black album, and *PERSONALLY* I don't think they've made a real hit album sence. A reasonable song here and there, but nothing huge.
Spice girls

(just because hopefully you've all forgotten about them by now)
Muse. 'cus I just can't care about their music.
Korn. A swing and for the most part miss band. Some good song, a LOT of crap. That's a part of the artistic proccess, I know, but you don't HAVE to release all the shite songs just to please the record companies (or whatever reason they do it for).
Scooter. On this one however, I migt be wrong. I suppose the music is more targeted to clubs and live preformances and stuff, but "dude had some mad hype going on" for a while.
Dragonforce. GuitarHero made their place in music history.