Justice League: A Better World
IMPORTANT NOTE: Earth-50 is not known as Earth-50 to the people who live in this parallel universe, as it happens to all the universes in the multiverse, each universe believes is the original one and the only one until the discover the existence of the other universes. Not all the universes or planes in this list have been discovered yet by the characters, nor is this a complete list of universes and planes.
Earth-0: aka New Earth aka The DC Universe: The Earth existing in the primary reality following the Infinite Crisis and Final Crisis events. Specifically referred to as Earth-0/Zero in Final Crisis #7.
Earth-2 : Formerly home to the Wonders of the World, including Superman, Batman and Wonder Woman, who fell in battle saving their world from the forces of Apokolips. Now defended by the likes of Doctor Fate, the Flash and Green Lantern, as well as Huntress, the daughter of Batman and Catwoman, Power Girl, the cousin and adopted daughter of Superman, and successors to Batman and Superman, among others. It is parallel to Earth 3 .
Earth 4 : Largely the same as Earth-4 of the 52 Multiverse and thematically inspired by Watchmen, this world is home to the Charlton characters such as Captain Atom, the Question, Blue Beetle, Nightshade and Peacemaker, with America having gone horribly wrong as a result of superheroes’ use as living weapons of the government. It is parallel to Earth 42. ( This link has an Obsidian Portal Page with stats for the Watchmen )
Earth-12 : Essentially the same as the DCAU, home of a future defended by Bruce Wayne’s successor Terry McGinnis as the Batman, alongside an aged Superman and the rest of the Justice League Beyond. It is parallel to Earth 50.
Earth-36 : Home to the superteam Justice 9, whose leader, Optiman, was slaughtered by the rampaging “Super-Doomsday” of Earth-45, before members Red Racer and Flashlight were brought to the House of Heroes to aid in the battle against the Gentry. The manipulations of The Gentry caused a zombified Optiman to appear and attack his teammates.
Earth-38 : Home to a Superman that debuted in 1938 and a Batman that first appeared in 1939. Unlike many of the worlds of the Multiverse, time passes on Earth 38 as it does on Earth Prime; its Worlds Finest team and other heroes aged over the course of passing decades, and eventually ceded their roles to their successors and children, beginning a heroic legacy that would continue well into the 30th century. Knight-Wing (grandson of both Superman and Batman), as well as potentially other heroes of this Earth.
Limbo: One of the Afterworlds.
Mount Olympus: Home of the Greek Pantheon.
Phantom Zone: One of the Lands of Logic.
The Dreaming: Shifting reality.