HOLY SHIT IT WAS AMAZING!! Usually, I inevitably get a little disappointed when a movie is hyped up so much, but this totally lived up to everything. Including the whole three year wait! God, it was so good.
FYI, the plot of the story is heavily based around the themes of the graphic novel The Killing Joke. (Even just reading a summary of the story will probably make obvious its connections to the film.) Never got around to reading it earlier, although I will definitely try harder to now.
EDIT: LOL @ IMDb