This really is my favourite moment from Christopher Nolan's Batman reboot.
Heath Ledger seems made for his role as the Joker. Beautifully manic and wonderfully watchable.
So here he is in Gotham's General Hospital and having found his way out sets about levelling the place bit by bit.
How? With a remote control detonator of course.
He steps out of the room and into the corridor .. BOOM!
Steps out of the building .. BOOM!
Walks away from the building toward a waiting bus .. nothing.
Frustrated and just a bit thrilled Joker fiddles with the buttons .. BOOM!
Haha! Superb and by all accounts a small amount of improvisation on the part of Ledger.