1. Matthew Lewis - Neville Longbottom
Cast as a child in the very first Harry Potter film, he's responsible for Neville Longbottom, arguably the character who undergoes the greatest transformation over the course of the eight films. He starts off as an awkward, chubby little boy with no discernible talents and a total lack of self-esteem. As the story goes on, he becomes a competent young wizard with a unique brand of courage. In a weird way, Matt Lewis has come out of the Harry Potter franchise as one of its most unexpected stars. His transition from dweeby little guy into a handsome man created quite a stir when he showed up for the final film premiere looking surprisingly like a debonair Clive Owen. He's even responsible for the expression, "pulling a Neville Longbottom", which is apparently when you start off as goofy-looking and make it through puberty not only alive, but really hot. So what is he doing now? Well, he was a recurring character on the second series of Bluestone 42, a war dramedy (sounds strange to put it that way, but let's go with it) about bomb disposal detachment in Afghanistan. Lewis was also cast in Our Boys, a play about wounded soldiers in a London military hospital, on the West End with Arthur Darvill. And he has what looks to be a major film in the pipelines called The Brontes, where he will play the brother of the famous Bronte sisters, which is due to be released sometime in 2016.