How about the ladies?
Davia Vallesillo of Dakoda Motor Co. (Good old rock band)
Wind and Sea,
Trip to Pain,
Truth
Sarah Meeker of Chasing Furies (Alternative)
Thicker
Korey Cooper of Skillet - (industrial) She doesn't sing a lot, but she's great.
Rebirthing (BTW, lady drummers are inherently hot).
Wilson lady from Heart.
Leigh Nash from Sixpence None the Richer (unfairly pigeon-holed by Kiss Me, a great guitar/alt/pop rock band)
Angletread,
Breathe Your Name You might not dig the music, but you can't knock the voice.
Any other lady vox?