Jessica Alba

Although this pouty-lipped vixen oozes sex appeal, she started out as a much more innocent-looking teen actress in numerous TV guest appearances as well as a regular role as a dolphin's best friend on the small-screen series Flipper. Alba segued to the big screen while still a minor, with supporting parts in Never Been Kissed and Idle Hands, both in 1999. The next year she became an instant star as a genetically enhanced messenger in the cult sci-fi series Dark Angel. With her perfect body and stunning face, Alba really did seem to possess designer DNA, and while the show only lasted two seasons, it was long enough for her to become a men's-magazine favorite and get engaged to costar Michael Weatherly. In 2003 Alba made the lackluster dance movie Honey and ended her relationship. But she reemerged triumphantly in 2005 with a new beau, Cash Warren, and two leads in blockbuster features — Sin City and Fantastic Four — which showcased her physical assets more than her talent.