No. 12: Taylor Momsen
Birthdate: July 26, 1993 (age 17)
Why She's Hot: As the Twitter generation's resident bad girl, Taylor Momsen knows how to gin up a controversy or two. The "Gossip Girl" star steadily earned rock 'n' roll points this year by shunning the likes of Rihanna and Miley, and fronting her own band the Pretty Reckless, in which she strips down to racy lingerie in music videos and occasionally catches heat for adopting Courtney Love's grunge-goddess persona. Critics be damned, though, because between TV, music and her new gig as a spokesmodel for Material Girl, the clothing line helmed by Madonna's daughter Lourdes, Momsen's got her market cornered.
Video Below: The Pretty Reckless' "Make Me Wanna Die"