5. Saorsie Ronan Hanna
Ok, so this ones a bit of a cheat. The part of Hanna herself is so off-the-wall that its quite literally insane a young teenage girl whos lived as a hermit, has no idea of social norms and appears to have an innate mastery of martial arts, MacGyvering (seriously, look at the crossbow-thing she makes in the final act) and ridiculous gunplay. Casting anyone for this role would seem like a bonkers move, but going after Saorsie Ronan looked even more ludicrous. Up to that point in her career, Ronan was only really known for the title role in the flawed Lovely Bones adaptation and as a secondary character in buttoned-up period drama Atonement, so to cast her as an ass-kicking action hero would seem a crazy move, at best. Critics knew she was talented but were nonetheless prepared to sharpen their knives regardless, anticipating something a flaming car-wreck. Yet they shouldnt have bothered the Irish teenager rocked in the part, somehow blending a child-like innocence with steely resolve as she bumbled through romantic situations with boys (they ended with submission holds) and married her love for fairy tales with her passion for blowing away rooms full of armed goons. It was a tricky balancing act to pull off, but she did it, and with aplomb.