47. Escape from the Planet of the Apes (Taylor, 1971)
By the time the plague was contained, man was without pets. Of course, for man this was intolerable. I mean, he might kill his brother, but he could not kill his dog!
Of the original series, this is, after the original and Conquest, the best one, and compared to the first two takes a lighthearted direction without diminishing the philosophical impact of the film. And then the (great) ending happens.