Transformation

Joseph Gordon-Levitt was a pretty cute kid in Third Rock from the Sun, but who knew he'd turn out to be so, well, crush-worthy? The actor has transitioned seemingly effortlessly from child star to leading man with movies like (500) Days of Summer, Inception and The Dark Knight Rises. And when he's not garnering acting kudos, he's producing everything from songs to stories to shows with his groundbreaking collaborative art collective hitRECord. Consider us crushed!

The baby-faced 14-year-old guest-starred on Roseanne.