Lady Gaga—seemingly always in stage makeup and underwear-like garb—is a one-woman hit factory. Teens stock their iPods with "Bad Romance," "Poker Face," "Alejandro," and "Telephone." Gaga is outrageous and R-rated, but at least she is a true musician. She writes her own hits, plays the piano, and sings (no lip syncing)—even when she dances on a ladder.