I use to loooooooooove gamesmaster, If I remember right it was outside of the usual kids TV programme times, like 6pm on channel 4 or something (crystal maze style).
I use to like it when the kid warped in front of the GM to ask some daft question like "on mario 1 how do I go down the pipes?" In the days before the internet and magazines were too expensive GM was the best place for cheat codes and the like.
Not really about GM, but anyone remember the Fred Savage film "the wizard" ? I remember that showing me where the first flute was on mario 3...... lols