Rihanna is no ordinary pop star. At 24, she has sold more than 47 million digital tracks, making her the best-selling digital artist ever. (She has also shipped more than 7 million albums.) The girl from Barbados has won armloads of Grammys as well, but tabloids often focus more on her turbulent relationship with ex-boyfriend Chris Brown, who pled guilty to assaulting the singer in 2009. In March, she collaborated on two songs with Brown, sparking controversy and rumors of a reunion.