21. Lucy Liu

Lucy Liu's first foray into the action genre was actually a small role in the Mel Gibson-powered Payback, but at the time, she was still mostly known for her role on TV's Ally McBeal. But then came the new millennium, and with it a new Lucy Liu, one that mixed it up with baddies as one of Charlie's Angels, which had Liu and co-stars Cameron Diaz and Drew Barrymore leaping, kicking, and blasting their way to box office stardom. She suffered a minor setback when actioner Ballistic: Ecks vs. Sever proved to be as terrible as its name, but when Quentin Tarantino came a-knockin' to cast Lucy as O-Ren Ishii in Kill Bill: Vol. I, she found redemption. O-Ren's Lady Snowblood-like ruthlessness reminded us that Lucy Liu could be as dangerous as she was exotic.

20. Jennifer Garner

Prior to landing her career-defining role as secret agent Sydney Bristow on J.J. Abrams' television show Alias, Jennifer Garner was stuck playing romantic interests in films like Dude, Where's My Car? and Pearl Harbor. However, once Alias hit the airwaves, the world found out just how lethal (and how buff) Garner could be. Hollywood soon took note, and Garner landed the role of the Greek-born, sai-wielding ninja assassin Elektra opposite future hubby Ben Affleck in Daredevil. Elektra rose from the grave for a subsequent spin-off movie, though critics beat it to death (zing!); Garner would pack heat once more as a terrorist-hunting FBI agent in 2007's The Kingdom.