Katherine Heigl

Biography: A former child model who conveniently plays an ex-model-turned-med-student on Grey's Anatomy, Heigl started acting as a teen. Initially she focused on the big screen (My Father the Hero, Under Siege 2), but at 21 she signed on to the sci-fi TV series Roswell. After the series ended in 2002, she appeared in a number of TV-movies before striking small-screen gold on Grey's Anatomy as an emotionally overwrought doc, a turn that earned her an Emmy in 2007. That same year, she starred in the comedy Knocked Up as an ambitious career woman who gets pregnant after a one-night stand with a schlubby loser. The film turned out to be a sleeper hit, which gave her career another boost and led to her alternating between television and film roles. In 2009, she and husband Josh Kelley adopted a daughter named Nancy Leigh, and Heigl enjoys spending her downtime hanging out with her family.