When I first started playing tabletop RPGs, there wasn't much more than D&D and Traveler. The person who ran the game was the Dungeon Master (DM) even if there were no dungeons in the game,
Later some games started using the term "Game Master" (GM) instead.
And then Call of Cthulhu called their game-runners "Keepers" (as in asylum keepers I guess), and things broke wide open.
But today, after over 40 years of running games, I realized that I'd rather be called a DM after all: a Dream Manager. Not that I run games set in Call of Cthulhu's Dreamlands (although as a long-standing fan of Lord Dunsany I've certainly used elements from that setting in some of my campaigns); rather, I see games as shared dreams made manifest by the interworkings of the game group.
That also removes the problematic "Master" part of the title, which always bothered me a little.