FUN FACT: This was improvised. The building was meant to explode and come down in one go and the crew had one take to get it right. When the explosions malfunctioned, Ledger reacted in character, and Nolan urged his crew to keep filming. By pure chance, it resulted in one of the greatest moments in the movie, and a moment that perfectly showcased Joker's archaic nature and Ledger's sheer talent.
Heath Ledger as the Joker, skate boarding over Christian Bale as Batman while they take a break on the set of The Dark Knight. You can all quit your lives now. Single greatest picture in the history of pictures and internet.