3. Iwan Rheon
Iwan Rheon is largely known for his quiet, almost creepily intense presence on television. On Misfits, he played the cripplingly shy Simon, who was doing community service for setting fire to his high school bully's house. It's almost painful to watch him attempt to interact with his peers, as he so desperately wants to be liked and accepted. All the same, if playing the shy lad was the extent of Rheon's abilities, he wouldn't be on the list. But in the second season of Misfits, we're treated to an even more multifaceted character, as we meet Future Simon. He's still reserved, and still has a certain tendency to stare a little too intensely at people, but there's also quiet confidence and assuredness in his movements that weren't there before. It's a tremendously subtle bit of acting, as we are expected to immediately see the changes in Simon but still believe that he is the same person. This is, of course, to say nothing of his mad, frenetic performance as Ramsey Bolton in Game of Thrones. Simply put, the young Welshman is gifted actor who should only continue his upward trajectory after his tenure on Game of Thrones is over.