Actor: Russell Johnson
TV Show: Gilligan's Island (1964-67)

Granted, Gilligan's Island is one of the most unbelievable shows to ever be strung together, explained in the 60 seconds before every episode (no further questions please). But the survivor team of full-grown children comes equipped with one professor, who helps them solve problems with inventions made out of coconuts. He is generally well liked on the island, especially by Mary Ann who is blinded by the light of his bamboo-fueled genius. Only, the one thing his inventions and schemes can never do is get them off of the island. Maybe it has something to do with the fact that he's actually a high school teacher.