10. Scarlett Johansson - Black Widow (Iron Man 2)
"What?!" you suddenly find yourself screaming into your computer screen, wondering what the hell is going on with this list already. "Didn't you see Captain America: The Winter Soldier, Sam? Scar-Jo was very nearly the best damn thing in it!"
Hold your horses, cowboy; you're absolutely right. But if we're going to get real about this Scarlett Johansson as Black Widow thing, let's be honest with ourselves: Johansson seemed horribly miscast in the role until that very movie; in both Iron Man 2 and The Avengers, she was actually kind of yawn-inducing. Which is to say, up until she decided to play the role with a little more gusto and personality in the second Captain America movie, Johansson seemed at total odds with the likes of Black Widow; there was a lacking sense of believability about her performance, and she appeared to have just opted to play it in the most generic way possible, adding nothing to the character.
Were we really convinced that Johansson was a super spy? Sure, she nailed the "hot" aspects of Black Widow's persona, but the rest seemed a little flat. Still, at least she's improved somewhat since.