Besided the Usual suspects Hendrix, Marley, Floyd
My fav is Radiohead (Ok Computer and later) For some it's an aquired taste, but once your hooked there is no going back.
Ok Computer and Hail To the Thief are the best CDs so far.
A song list...
Fake Plastic Trees, Subterranean Homesick Alien, Lucky, Everyhing In It's Right Place, How to Dissapear Completely, Punchup At A wedding, The Gloaming are good songs to start.

you may want to try some Portidhead. A nice trippy hip hop R&B sound.
Songs...Strangers, Glory Box, Mourning Air, Undenied... to start

Bjork is a blast as well