One of the stranger iterations of Batman out there, Earth-494 is home to Captain Leatherwing, a Batman-inspired buccaneer who sails the Seven Seas aboard his ship, The Flying Fox, during the Golden Age of Piracy.
Set at the tail end of the 19th century, Earth-19's Batman features a gothic portrayal of the Dark Knight in 1889 Gotham, who begins investigating a series of murders that seem to be the handiwork of the still-at-large serial killer, Jack the Ripper.
In this version of Earth, Batman's secret identity was made public knowledge decades prior. Now an old man, Bruce Wayne wears an exoskeleton suit and is known for transforming Gotham into a police state, using his "Bat-Knight" drones to patrol the city.
In this version, Batman and Superman are based in the Soviet Union. The most entertaining aspect of this version of the Caped Crusader is not his awesome attire but his hard morals and the mystery around him.
This version of Batman initially battles the vampiric lord Dracula before succumbing to his wounds and eventually becoming a vampire in his own right.
Earth-12 is a futuristic version of DC's Prime Earth, home to the Terry McGinnis version of the Batman, better known for his starring role in the animated series, Batman Beyond.
Earth-31's Bruce Wayne is an older, retired version of the Dark Knight who opts to take up the cape and mask one final time to once again strike fear into the hearts of Gotham's criminals.
Earth-22's Batman (also known as the Batman Who Laughs) is basically a cross between Batman and his regular archenemy and the definitively best Batman villain of all time, the Joker.