When it comes to DC Comics and the DCEU movies, Joker is always the villain people think of first. It helps that he is one of the oldest villains in DC history, appearing in Batman's very first issue as well as the first Batman movie. He is also the villain that won an actor the first Academy Award for a superhero movie.
Joker is back in the news again thanks to the 2020 comic book series Three Jokers, which offers up an interesting take on who Joker is and why he has always been able to reinvent himself over the years. However, with 80 years of history, it might seem daunting to find a reading order for Joker comics; however, here a good start if a person wants to follow the Crown Prince of Crime's career chronologically.
Batman #1 (1940)
The most interesting thing about Joker is that there is no actual origin story for him. In the movie The Dark Knight, Joker tells several origin stories and then reveals that none is likely true. While the first Batman movie showed an origin, it is not canon in the comics.
The best starting point for reading Joker's stories is his first appearance, which came in Batman #1 in 1940. In this issue, he is a cold-blooded killer who murders people and steals their valuables.
Detective Comics #168 (1951)
The main idea is that Joker was a common criminal known as Red Hood, who Batman stopped, causing him to fall into a vat of chemicals, scarring him, bleaching his skin, and driving him insane. In Detective Comics #168 in 1951, Red Hood is back, and he is trying to rob a university, claiming to come out of retirement for the job.
However, when Batman catches him, he reveals he is not the original Red Hood and kidnapped the original, who turned out to be Joker. This is where he admitted to falling into the vat of chemicals and becoming Joker.
Detective Comics #475-476 (1978)
Something happened to Joker in the '60s and '70s. He went from a ruthless criminal who killed people and stole their valuables to a jokester who would almost rather kill people by pulling pranks than steal anything.
It was a big change, and the best issues that show this came in Detective Comics #475-476, where Joker created a toxin that created fish with Joker's face on them. His goal was to copyright the Joker Fish, and when refused, he began to kill city bureaucrats until Batman finally stopped him.
Batman: The Man Who Laughs (2005)
In 2005, Ed Brubaker and Doug Mahnke wrote the one-shot issue Batman: The Man Who Laughs. This issue, despite being released in 2005, is an old story. This goes back to the year after Batman started fighting crime, and Commissioner Gordon was trying to find a way to get control over the organized crime in his town.
This ended up being the first time that Batman and Joker battled in the post-"Crisis on Infinite Earths" timeline. The story did a few things, including showing Batman what caused Joker's madness and showing that the one-time clown was now a sociopathic murderer.
Legends of the Dark Knight #65-68 (1994)
The four-issue Joker-centric run in Legends of the Dark Knight #65-68 tells the story of the third time Batman and Joker ever fought. In this series, titled "Going Sane," Joker believes he killed Batman and then realizes he has nothing left to fight and chooses to give up his life of crime and has created a new name and life for himself. However, his happy life is ruined when Batman returns, and he becomes Joker again.
Batman: The Long Halloween (1996)
Batman: The Long Halloween came out in 1996, created by Jeph Loeb and Tim Sale, and once again was a story from Batman and Joker's past, this one also following the Batman: Year One story. The story places Batman and his villains in a noir-styled world with gangsters running Gotham City.
It also features the origin of Harvey Dent, showing how he becomes Two-Face. Gang lord Carmine Falcone hires several Gotham City villains to stop Batman but never realizes how powerful they are, Joker included.
The Killing Joke (1988)
The most famous, and somewhat controversial, Joker storyline in history came in 1988 with Batman: The Killing Joke. This was Alan Moore and Brian Bolland's story that had Joker commit his darkest crime. This issue also revealed the origin story of the Comedian version of Joker, which was later confirmed to be accurate.
In this issue, Joker decided he wanted to drive Commissioner Gordon crazy and see if he could push Gordon into committing murder. To do this, Joker shoots Barbara Gordon and paralyzes her. For years, this meant Batgirl became Oracle, and in the end, Gordon remained a force of good.
A Death In The Family (1988)
The same year that the Comedian Joker shot and paralyzed Barbara Gordon, an even bigger murder happened. What was revealed later was that the Clown Joker was responsible for an actual murder of a member of the Batman family. "Death in the Family" is infamous as fans were allowed to vote on whether Jason Todd lived or died, and the votes came in to kill Robin. That is what Joker did in this book, and it drove Batman to despair for many years.
Arkham Asylum: A Serious House on a Serious Earth #1 (1989)
Arkham Asylum stands front and center in the book Arkham Asylum: A Serious House on a Serious Earth. Grant Morrison and Dave McKean created a book like no other, as Joker and Black Mask took control of the Asylum from inside and held hostages demanding that Batman come and follow their orders, or they would kill everyone. This is the book that influenced the videogame Batman: Arkham Asylum years later.
Death Of The Family (2012)
The DC New 52 changed the origins of most of DC Universe's characters, like "Crisis on Infinite Earths" did in the past. However, Batman remained mostly the same, with minimal changes outside of some new villains. However, when Joker returned, he was more deranged than ever.
In homage to the death of Jason Todd, the big Joker crossover was titled "Death of the Family," Joker cut his face off and escaped from Arkham, and when he returned, he began to target the GCPD as well as members of the Bat-Family. While Batman won the fight, this was the one time that Joker beat Batman by turning his own family against him.
Three Jokers (2020)
The most recent appearance of Joker in DC was Three Jokers in 2020. This was a three-issue series that revealed one of the biggest secrets about Joker. Through the years, it was not one man, but three. There was the Criminal, from the early years of Batman, the killer, and thief. There was the Comedian, who was who shot Barbara Gordon in The Killing Joke. Finally, there was the Clown Joker from the '60s and '70s, and the man who killed Jason Todd. This series tells their stories.