Whilst a lot of people focus on the darkness and brutality of the film which certainly holds appeal, I think something overlooked is the fact a comic book villain has never had a true origin story and they deliver this in a beautiful way.
......If you ask me it's about time.
I also think for me the man joaquin phoenix starts out to be could be the joker heath ledger portrayed.
It is one of THE best films I've ever seen, I'm an art form, for a movement simply for the average filmgoers. It ticks all the boxes nothing short of a masterpiece.