Crossover Kid (Age: 26)

It's Lil Wayne's world. No question about it. In June, the diminutive MC, who calls himself "the best rapper alive," defied a decade of nosediving music sales by moving more than 1 million copies of Tha Carter III in its first week—surpassing Mariah, Madonna, and the rest of the industry. Credit his lyrical skill, fecund imagination, and ingenious wordplay, but don't overlook the man's guitar-strumming, flannel-wearing appeal. "As a rapper, maybe you shouldn't have that quasi-skater Hot Topic vibe, but he pulls it off," says Hillary Crosley, the hip-hop and R&B correspondent for Billboard. "He can jump on a silly song with T-Pain, a serious song with The Game, or a Euro-dance track with Kevin Rudolf. You can't be more pop than that." Or more ubiquitous. Between his LPs, his mix tapes, and his collaborations, Lil Wayne seems to release something new every day—often free of charge on the Internet. He even got an endorsement from Michael Phelps, who pumped up with "I'm Me" before crushing his Olympic competition. Get used to Wayne's world. He isn't going away anytime soon.