I grew up near Lake Geneva, Wisconsin, ancestral home of D&D and TSR until 1997. The Game Guild, perhaps the first modern game store in the U.S., was my old stomping ground, where I cut my teeth on RPGs. I played with some fantastic GMs before I even know what made a good GM.
Trouble is, I don’t remember most of their names.
I *do* remember Dave Hankle. He ran an epic game. And I mean that literally, not in the “high-level character” sense. His game was expansive, beyond what we know of today as a megadungeon. With an inordinate number of players. I tried a game with nine players once, and it was too many to keep track of, yet Dave would run games with a dozen or more and every player was engaged and interested, somehow. Amazing.
Was he the best? Probably not, but he was definitely up there.
Thing is, I can find something to enjoy about almost any game, even if the GM stinks. For me, the best GM is one who wants his players to have fun, and has fun doing it.