Watched the movie four times, and not once did any scene get boring...
Plus, this dude is just awesome! :-)
A few exchanges/dialogues i really enjoyed...
The Joker: “I believe whatever doesn't kill you simply makes you... stranger.”
The Joker: “Why So Serious? Lets put a smile on that face...”
Harvey Dent: "You Either Die a Hero, or Live Long Enough To See Yourself Become the Villain"
The Joker: "Y'see, madness, as you know, is like gravity. All it takes is a little...push.”
The Joker (to Rachael) : A little fight in you. I like that! Batman: Then you're going to love me.
The Joker: You just couldn't let me go could you? This is what happens when an unstoppable force meets an immovable object. You truly are incorruptible aren't you? You won't kill me out of some misplaced sense of self-righteousness, and I won't kill you, because you're just too much fun. I think you and I are destined to do this forever.
The Joker: The only sensible way to live in this world is without rules!
The Joker: If you're good at something, never do it for free.
Bruce Wayne: So, let's put a couple tables together. Harvey Dent: I'm not sure they'll let us. Bruce Wayne: Oh, they should. I own the place.
Lucius Fox: Let me get this straight: You think that your client, one of the wealthiest, most powerful men in the world, is secretly a vigilante who spends his nights beating criminals to a pulp with his bare hands. And your plan is to blackmail this person? Good luck.
The Joker: Oh, and you know the thing about chaos? It's fair.
P.S. Its the Joker who has left a lasting impression on the minds of the viewers, and not the Dark Knight.
