Ledger's Dark Knight.

First of all, Heath Ledger earns and deserves all the acclaim he has been getting for his gruesome embodiment of the Joker in Dark Knight. Everyone else in the film, good as they are, pale by comparison. Their characters succumb to the nihilism the Joker exudes. When the film tries to win us over to some sort of faith in humanity, it simply is not convincing. The Joker is so evil that the mob bosses of the film are mere dilettantes, mere marionettes pulled apart by their new mastermind.

The Joker
from Wikipedia

But is this a great film? Given that it is a marriage of comic book with sophisticated cinema technology and hip psychoanalysis, no. The sheer loudness of the film, the techno film world's equivalent of "Pop!" and "Crash!" of the comic books, is just too over-bearing to let the dark philosophy and character development succeed. The strange love triangle between Batman, the D.A. and Rachel Dawes works only as one more path of destruction for the Joker. The character of the D.A. becomes a sick and tortured Dudley Do-Right. It works only on the comic book level.
Yet, the film is highly entertaining and provocative. If it falls short of greatness, it nonetheless represents a new order of film noir: giving us crime, murder, sexual ambiguity, a femme fatale, and psychological terror.
The Joker and Heath Ledger will haunt our psyches for a long time.

Jack