GM/DM. Making up worlds, cultures, creatures, adventures, and magics is the better part of why I'm into this hobby.

It also gives you power, which is not intrinsically bad. The GM has authority to shape a lot about the pace, tone, and feel of the game, and I think that power well worth the responsibilities which accompany it; and if a rule system has frustrating or badly thought-out elements, I like being in a position to remedy them directly.