5. Chris Hemsworth

2011 key role: 'Thor'

Chris Hemsworth made such an impression as George Kirk (James's doomed father) in the prologue to 'Star Trek,' it seemed inevitable that stardom would find him. It did in 2011 with 'Thor,' where the mostly unknown Australian actor starred as the titular Norse god in a film that earned almost $500 million worldwide.

Upcoming projects: Hemsworth will be on Thor duty for some time -- in addition to 'The Avengers,' out next summer, he'll also star in 'Thor 2' -- but the young actor has quite a busy lineup of non-Marvel films on the calendar too: in addition to the long-delayed duo of 'Red Dawn' and 'Cabin in the Woods,' Hemsworth will co-star with Kristen Stewart and Charlize Theron in franchise-starter 'Snow White and the Hunstman' (he's the huntsman), as well as the race-car drama 'Rush' for director Ron Howard.