Batman #1, published in 1940, is a highly sought-after comic book among collectors. This issue introduces Batman's iconic sidekick, Robin, and features the first appearance of the Joker. The story follows Batman and Robin as they try to stop the Joker's crime spree in Gotham City. With its dark and gritty artwork, Batman #1 is a classic piece of comic book history that showcases the early days of the Caped Crusader's crime-fighting career.