Depeche Mode - i have all of their albums on my iTunes, including remixes and Greatest Hits compilations
Slipknot - i have had all of their albums, i have been a fan for a loooong time
The Crystal Method - i am missing a few albums, but my favorite has always been Community Service 2, the Doors mix is one of the best songs i have ever heard in my entire life. just sayin'.
Loreena McKennitt - i have all of her albums, even the Christmas ones
Azam Ali - i have every album she has ever put out, as well as her project band called Niyaz and i will include the 300 soundtrack in this as well because she did all the vocals
Enigma - i am missing one or two, but one day i'll have tracked them all down
Delerium - i used to have all of them, but i lost a ton when my old pc died
Rasputina - missing one album, i think, otherwise i have them all
and... that's pretty much it. maybe Florence + the Machine and Mumford & Sons when they put out more albums.
yes, i have weird musical taste, you don't have to tell me this i already know.