Clooney was only at the beginning of his transition from "ER" TV star to full-fledged movie star when he took on the "Batman & Robin" role. Now one of the biggest movie stars in the world, he counts films such as "Ocean's 11," "O Brother, Where Art Thou?" and "Tomorrowland" to his name. He's also earned Oscar nominations for his acting in "Up in the Air," "Michael Clayton" and "The Descendants," winning Best Supporting Actor for 2004's "Syriana." He's also earned additional Academy Award nominations for his work behind the scenes as a writer, director and producer.