I'm trying to find all the girls that can truly rock... not like pop-rock (ie michelle brach, avril)

These are the ones that I can think of:

Courtney Love
Melissa Auf der Maur
Gwen Stefani (in No Doubt, not her solo)
Kelly Osbourne
Liz Phair
Patty Schemel
Samantha Maloney
Shirley Manson (of Garbage)