It is by far, the best portrayal of the Joker to date.

Rating: 10/10 (19 May 2015)

This was an astonishing and ultimately the best comic-book film made, and even made the best comic-book villain portrayed by a great actor who played his character well and live in our hearts forever.
"The Dark Knight" was well composed, sequences amazing, and the story was magnificent. So many reasons as to why Heath Ledger made the Joker the way he was and made him so perfect are ways that no person - I believe - will ever be able to beat.
Having so much enthusiasm for the role, by locking himself up for 6 weeks to come up with the menacing voice and terrifying laugh that he created, absorbing the mental stability of a psychopathic schizophrenic with acute PTSD, no one can match his dedication (even though rumoring about Heath taking meds to make the character seem more twitchy - I believe - was not the case or one of the reasons he made the Joker his best role).
Heath is the reason how the Joker and the film one of the greatest films of all time.