8. Jessica Alba
At twelve years old, Jessica Alba took her first acting class. Nine months later, she was signed by an agent, and the rest is history. When she was 13, she got her first movie role as Gail in Camp Nowhere. That same year she was featured in The Secret World of Alex Mack on Nickelodeon. By the time she was 14, she had a recurring role on Flipper and was getting regular television work. Lately, she's been doing a lot of work in a certain niche market. Her work in cult favorites such as Sin City and Dark Angel has assured her popularity, and she continues to be attached to prolific projects. Within the next year she's slated to work on the anticipated Sin City sequel, as well as the latest Robert Rodriguez film.