39. Katy Perry
Band Or Solo Artist?: Solo
Greatest Hit: "I Kissed A Girl" (2008)
It's hard to believe our ever-sexy former cover girl was once a gospel singer whose ultra-conservative parents forbid her to listen to pop music as a teen. Now, Perry's crazy tour costumes—think cupcake bras—and pop music have made her one of this decade's most googled women. Even her first hit, "I Kissed A Girl" broke pop boundaries with sexual lyrics about females experimenting with females. These days, she's working on her fourth studio album and living it up post-divorce from funnyman Russell Brand.