Always loved some of the quotes from Harry Potter - Sirius Black and Dumbledore having the better ones.

"If you want to know what a man’s like, judge him on the way he treats his inferiors, not his equals.”
— Sirius Black

Obviously this depends heavily on one's interpretation and subsequent extrapolation of the current geopolitical climate. That being said Nazis, the Soviet Union and generic Middle Eastern terrorists will eventually fall out of vogue and lose their cultural significance with each passing generation. What might come next?

If nothing else, I suspect zombies will remain one of those recurring trends that come in waves.