Writer: Alan Moore
Artist: Brian Bolland
By putting the spotlight squarely on the Joker in this psychologically intense one-shot, Alan Moore forever changed the relationship between the Caped Crusader and his fiercest villain. By peeling back the deranged layers of the Joker’s twisted psyche, Moore succeeded in rationalizing how the senseless nature of the world could turn a seemingly normal man into a homicidal supervillain.
This is the first story to really take a look at the events in the Joker’s life before he became a psychotic menace, and there is a sense of compassion we feel for him throughout the narrative. This isn't a man born evil; instead, he simply became a victim of the random and tragic nature of the world forever twisting his mind.
In between the flashbacks to his origins, Moore also tells one of the most violent Batman stories of all time. The main plot deals with the Joker breaking out of Arkham Asylum. Afterwards, he commits one of the grisliest acts in DC's history by shooting Barbara Gordon through the stomach, paralyzing her forever. This is all in an attempt to drive her father, Commissioner Gordon, insane and prove to the world that even the most upstanding citizen can be driven mad after a bad day.
If you want to see where Heath Ledger’s inspiration came from for his performance as the Joker, then look no further than The Killing Joke.