The daughter of two Olympic rowers who competed in the 1976 Montreal Games, Mariel Zagunis, 27, was crushed after she failed to qualify for the 2004 Olympics in Athens. But a last-minute spot opened up, and Zagunis took full advantage: she became the first U.S. fencer in a century to win gold. She repeated her individual gold in Beijing in the sabre discipline and added a bronze in the team event. Zagunis has helped raise the profile of her sport as well: she won world titles in 2009 and 2010, and one of her sponsors, TD Ameritrade, featured her in a Times Square billboard this spring.