DarkCrisis
Takhisis' (& Soth's) favorite
Modern with some Renaissance stylings. Or, more accurately, a fantasy world with no connection to real world history.
D&D has never had an official setting that was medieval.
Modern? What defines modern? I have yet to see Faerun heroes cruising to the dungeon in a pick up truck.
Greyhawk maybe? Krynn despite the wacky gnomish Steam stuff. Dark Sun is very regressed. You won’t find any flintlocks there I think.