Hard call. It really is a toss up between my home brewed Mystoerth campaign world for *D&D or Victorian England.
Mystoerth grew out of a need for my then DM and I to merge our worlds. He was a huge Greyhawk fan (as was I, but less so) and my world was the known world of Msytara.
|Map by Rich Trickey aka chatdemon|
We did not call our world Mystoerth. That name as far as I can tell came from +James Mishler and +Rich Trickey. Rich made that nice map.
It has worked well for me over the years.