6. Detective Comics #27 The Retconned Golden Age Joker (1939; 2014)
Batmans first adventure was published in Detective Comics #27 (1939). Here we are given the tale called The Case Of The Chemical Syndicate, which focused on a group of businessmen who owned the Apex Chemical Corporation. One of the men, Stryker, made a deal to pay each of the partners a sum of money yearly until he owned the company. He eventually grew impatient with waiting and hatched a scheme to kill his partners and take control of their shares of the business. When Batman shows up to stop Stryker, he hits him so hard that Skryker breaks through a railing and falls into a tank of acid. Although this story has much in common with the aforementioned The Man Behind The Red Hood, this was never the official origin for the Joker until 2014. During 2011 DC rebooted and renumbered their line, and when the renumbered issue of Detective Comics #27 (2014) was released, they used it as an opportunity to celebrate the 75th anniversary of Batman. This super-sized issue was a compilation of Batman stories, which also included a retelling of Golden Age Batmans first adventure by written by Brad Meltzer with art by Brian Hitch. At the end of this retold story, Meltzer potentially offers a new origin for the Joker, as we see Strykers marred hand reach up out of the acid bath. Meltzers retcon has possibly fixed a continuity problem dating back to the 60s by making Stryker the Golden Age Joker of Earth Two and thereby establishing that the 1951 Red Hood origin was indeed the Silver Age Joker of Earth One.