15. Shirley Manson (45)
With 12 million+ albums sold, and cited as a major influence by everyone from Skylar Grey to Taylor Momsen, Shirley Manson is the archetype of the modern-day rock chick. As the voice of seminal '90s band Garbage, she proved that women could rock just as hard – if not harder – than their male counterparts. The hits flowed for more than a decade but the fiery redhead pulled the plug on Garbage in 2005. Happily, the “Battle In Me” vocalist has revived the band for one of 2012’s most eagerly-anticipated comebacks. You just need to watch Shirley’s surreal starring-role in “Blood For Poppies” to see that she’s still got it.