Sure most people use Dungeon Master for D&D games or Game Master for others but I like the term Judge just like the guys at the eponymous Judges Guild use.
It seems to me that Judge implies a more neutral less adversarial relationship than "Master" and gives people especially non gamers a good idea what exactly I do.
I judge the actions taken in game and the worlds response to them.
Nice and simple.
The Return of Planescape? - Curious. There is a brief note on this 'countdown' at Enworld.
13 hours ago