Rihanna You can't talk about celebrity transformations without putting Rihanna at the top of your list. Rihanna went from island sunshine sweetheart to Bad Girl Riri in the blink of an eye, and it looks like she has no intention whatsoever of going back to her sickly sweet pop star days.
Christina Aguilera Who can forget how scandalous the "Dirrty" video was? It was so dirty it needed two Rs, apparently. And the lyrics, which were all about getting "filthy" and her "arrival" as a new (dirtier) person, was basically an announcement introducing the new Xtina.
Lindsay Lohan After Mean Girls, everyone had Lindsay Lohan pegged as the next big teen star. Instead, Lindsay found herself dealing with a string of arrests and rehab stays, as well as being mercilessly ridiculed by the media.
Miley Cyrus Miley's transformation from Hannah Montana to the twerking, tongue-wagging Miley we are forced to hear about today is one of the most well-known cases of celebrity rebelliousness to date.
Angelina Jolie Angelina may be a socially-conscious humanitarian these days, but remember when she used to make out with Billy Bob Thornton on red carpets and wear a vial of her boyfriend's blood around her neck? Yeah, that was weird.
Kelly Osbourne We were first introduced to Kelly back when The Osbournes was airing on MTV. Since then, she's completely reinvented herself, going from outspoken punk girl to still-outspoken fashion maven.
Drew Barrymore Drew Barrymore got her rebellious phase out of the way early on in life. As a child star, she was smoking and drinking before she was 12, and had moved on to cocaine by the age of 13. Luckily, after a few stints in rehab, Drew got herself onto the right path.