Um, all of the above?
I mean, it is my attitude that I should provide the players with fun... but I do that by properly balancing encounters, providing interesting adventures, and giving the players a fair shot, not by fudging rolls. The anxiety of possibly losing (or at the very least, have disadvantaged) their character is part of the fun and emotional content.
I am an arbirter. I am a genre emulator, not a media emulator.
I am a player. I try to have as much fun with my characters and plots as the players are having.
I am a creator... this is my playground, my toy, my sandbox.