8. Bradley Cooper
Bradley Cooper's career has been steadily on the rise after the unprecedented success of The Hangover in 2009. He's starred in 13 films since then, and was nominated for a Best Actor Academy Award for his performance in David O'Russell's 2012 film, Silver Linings Playbook. He's reuniting with O'Russell later this year in American Hustle, and just got cast as Rocket Raccoon in Guardians of the Galaxy, the highly-anticipated space epic from Marvel Studios. Cooper may not have become a superstar until 2009, but got his start twenty years earlier in an episode of Sex and the City. He was then cast in his first movie, Wet Hot American Summer, before joining the cast of JJ Abrams' show, Alias. He then kept fairly busy in both TV and film, starring in movies like Wedding Crashers, Yes Man, and He's Just Not That Into You. And, let's not forget one of the highest achievements a Hollywood actor can obtain: he was named People magazine's Sexiest Man Alive in 2011. If that's not success, I don't know what is.