I'm a fan of the Great Wheel in concept, if not in all its environmental details. So I'm curious what others think -- are there fantastical environments you wish had made it into outer plane-hood, or layer-hood? Or maybe you wish one of the outer planes was just a little different? Bonus XP if your wish has a mirror-image opposite, such as...
Mechanus is much as canon presents it; an enormous mechanism of interlocked cogs existing in an endless sky.
Limbo is its mirror-image opposite; an infinite variety of islands and continents floating through an endless sky, which often bump or crash into each other.
I have always been partial to the Wild West reboot that got bandied about at
/forum/wild-west-planes
As they stand, the Outlands seem a bit bland to me; so the Wild West rewrite provided more color and it gave a place for a genre that didn't fit anywhere else on the planes