The Treasure of Jamaica Reef (1975). Fascinating illustration: the shark is not a reflection in the diver's mask, as it first appears, but the position over his left eye implies they are "eye to eye," which creates tension, danger, and interest to see the movie.
Starcrash (1978). The exciting promotion art shown here does not match the energy of the movie; or budget; or thematic excitement. It also rips off the Star Wars spaceships and original poster artwork.