A professor faces ridicule unless his claim that Ben Hur was a real person is supported. Superboy goes back in time to prove the existence of the fictional character.
Aquaman uses Tommy Leeds, a lookalike who can't swim, to impersonate him so he can appear to be in two places at one time. In doing so, he restores Tommy's luster in the eyes of his girl friend who thought her beau was rather dull.
Your usual story in which aliens kidnap a "typical" human and decide not to invade earth because Earthmen are so tough. Johnny has trouble with his formula in space and has to use several randomly chosen variations.