I talk a lot about Dungeons & Dragons. I also talk a lot about Game Masters, but I don’t say much about Dungeon Masters.
When I’m talking about the role of the Game Master, regardless of the game I’m talking about, I always use the words “Game Master,” or the abbreviation “GM.” More often, I’ll spell out the whole title for the same reason you’ll never see me call a “player character” a “PC” (a PC is a computer, GM is an auto manufacturer).
I believe in a common lexicon for gamers. I believe that by calling the role of the Game Master something else, we are diluting that lexicon for the sake of distancing ourselves from other games. To call your Game Master a “Dungeon Master,” or a “Storyteller” or a “Referee” is to call an apple a “gremith,” or a “speloink.” An apple is a fucking apple. Calling your apple something that isn’t “apple” just makes you an asshole.
The only exception I’ll allow is for some indie games, in which you call the Game Master something for flavor reasons. But if a game like Dogs in the Vinyard can get away with calling you a Game Master, I can’t imagine many games needing to do away with the title.