Hilary Swank

If there's one thing you can count on, it's Hilary Swank putting her blood, sweat, and tears into a role. For her performance in Boys Don't Cry (1999), in which she plays a young trans man, Swank lost weight and lived as a man for two months. Her preparation paid off as she was the Best Actress winner at the 2000 Academy Awards. She won again in 2005 for her work in Million Dollar Baby (2004), and although she had just turned 30, it's still an impressive feat as only a handful of actresses have been nominated for and won Best Actress twice.