Like many contemporary teen crushes, this charismatic Canadian started out as a precocious performer on Disney's revamped Mickey Mouse Club. As a clean-scrubbed youth in the early '90s, Gosling belted out boy-band songs in falsetto alongside the likes of Justin Timberlake, Christina Aguilera, Britney Spears and J.C. Chasez. But unlike his MMC costars, he switched his focus to acting, and by the end of the decade he had built up an impressive résumé in a number of juvenile-oriented TV series, notably as the title character in the short-lived action-adventure series Young Hercules. In 2001, he shattered his cute-kid image with his breakout role as a zealous anti-Semite who happens to be Jewish in The Believer. Gosling continued to excel at playing complex, troubled characters: a high-school student turned killer in Murder by Numbers (which introduced him to ex-girlfriend Sandra Bullock) and a troubled youth trying to survive juvie in The United States of Leland. But it was his charming performance as a poor lovesick boy in the popular romance The Notebook that caused women of all ages to swoon, including his costar-cum-girlfriend Rachel McAdams. Ever the rebel, instead of opting to become Hollywood's next leading hunk, Gosling wisely returned to his dark side in Half Nelson, earning SAG and Oscar nominations for his riveting turn as an inner-city teacher struggling with a crack habit.