26 lettered Earths, 1/x
Aerth - fantasy historical Earth: the fun parts. pre-gunpowder (it doesn't work) but other than that all your favorite historical eras squished up against one another. Earth-Xena, if you will.
Bearth - Earth but populated by evolved bears and other ursines
26 lettered Earths, 2/x
Cearth - Celtic catgirl/catboy earth. the sidhe and unsidhe clowders alternate being "ruled over" by Tom Tildrum or Tim Toldrum. see also, the Taìn.
Dearth - not a lot here, kinda miserable and gloomy, scarcity reigns except for gunpowder, gasoline, and greed
26 lettered Earths, 3/x
Earth - our Earth. most portals or other means of transit are laden with "enter at own risk"-type signifiers
Fearth - horror Earth. gloomy and foreboding. all the little horror subgenres of the past two-odd centuries get their little Ravenloft-style demesnes
26 lettered Earths, 4/x
Gearth - clockwork, steampunk, Victorians, extremely tiresome except for the modrons! i love those little guys
Hearth - halflings came from here, it's pretty cozy
Iearth - crystals, psionics, high magicks, home of the IOUN stones
26 lettered Earths, 5/x
Jearth - something about the light casts everything in shades of blue
Kearth - possibly Korean Earth, a never-divided Korean Empire as a major world power and cultural force.
26 lettered Earths, 7/x
Oerth - home of the Flanaess, the Circle of Eight, Vecna, the City of Greyhawk, etc. sports a deceptively stuffy and tedious surface over an amoral and murderous core. Oerth wasn't placed at the center of creation as its denizens claim, but they *are* awfully close to it.
26 lettered Earths, 8/x
Pearth - an odd, bottom-heavy planet, sparse population concentrated largely in the southern hemisphere, a strongly independent people who speak a deeply drifted dialect. everything also has a real juicy donk for some reason.
Quearth - gay, gay, gay