Which minifigure configuration has been included in the most sets? I'm looking for the color of the head, arms, hands, legs, pelvis, and torso as well as the facial expression and any headgear. Please include an image of this minifigure doppleganger.
So far, the best I can think of is the red classic space guy which appeared in 46 sets.
Considering minifigs were less specialized back then, I bet the winner is in that time period anyway, and the fact that spacemen wore an uniform makes me think there is no other minifig apperaing in 46 sets. Even the basic city worker only reaches a pale 21 sets.
The Skeleton with Basic Skull appears in 42 sets. If you include the sets that have the same figure only with different headgear, the number of sets is 56.
If you had one of every set in peeron's database:
Torso: 973 - A plain torso - Black
Head: 3626ap01 - Normal plain smile - Yellow
Legs: 970c00 - Plain legs - Black
Their database is not complete, I haven't been able to find data for colour of hands or arms, and this is for each peice individually, not the minifigure as a whole, but I think it's the best that can be done.
This image isn't very good quality, but I had a go in Photoshop...