1. Heath Ledger - The Joker - The Dark Knight (2006)
I don't think it could have been possible for people to have been more blown away by Heath Ledger's insanely good performance as Batman's iconic arch-nemesis, simply because they'd spent the months building up to The Dark Knight's release saying mean things and preparing their top ten lists as to why Jack Nicholson is and always will be the best Joker ever. And yet, there we all suddenly were, looking at what can only be described as a truly transformative performance - the Ledger we all thought we knew was nowhere to be seen. What was it about Ledger that everyone got wrong, then? What was it that convinced the world he was wrong for the part? Well, perhaps it was the fact that - at the time - he was best known for rom-coms, A Knight's Tale and "that gay cowboy film." There wasn't really any evidence to suggest he could play... well, totally and utterly insane, I suppose. Of course, nobody knew how much effort Ledger was putting into his performance behind the scenes, but it all totally paid off: he won, like, every major award ever in the aftermath, including a posthumous Oscar.
So why don't we just sit back, relax, leave Ben Affleck alone for a while, and give the poor guy the benefit of the doubt? Failing that, leave your angry words in the comments section below.