The Monitors (1969)

Unusual sci-fi invasion film, with a black-comedy twist: The Earth is taken over by The Monitors, aliens who run it like hall monitors in a 1950's high school, with overtones of Big Brother. The film follows the progress of the human underground rebellion. The twist is that as the film goes on, the audience's sympathies shift to the aliens, who are basically benevolent. When the humans manage to oust them, it's back to corruption and bribery by the usual suspects.