You've remembered everything in the Forgotten Realms. You've added a bit of color to Greyhawk. You've tinkered around in Eberron. You're looking for a new setting to set your game. How about Fading Embers? It's a new fantasy campaign setting, the primer of which is up on Kickstarter now.
From the campaign:
The Fading Embers Setting Primer is a preview of a full campaign setting built for the 5th edition rules. It will provide a breakdown of the history and nations in the setting, as well as newly created races, classes, spells, magic items, monsters, and adventures! So even if you prefer a different setting, you'll still receive exciting new material to be used in your own games!
The campaign's a little more than halfway to their goal with 26 days left.