Kelly Clarkson entered the spotlight in 2003 as the first American Idol. But since then, she's become the show's quintessential winner, fulfilling its promise of creating a pop superstar with her aw-shucks charm and undeniable voice, which can handle nearly any genre that's thrown at it. “Since U Been Gone” gave a sugar-sweet gloss to early-'00s pop rock; “Invincible” supercharged a gospel-tinged assertion of strength. Clarkson's talent and charm tie disparate types of music together in a catchy, emotion-stuffed package—the mark of a true pop star.