I name the combined plot, you guess the combined movie title and write your own combined plot:
A normal-looking girl and her family travel in a van to a clinic where more conventionally pretty girls get their memories erased.
A: Little Miss Eternal Sunshine of the Spotless Mind
A butler and a housekeeper never admit their true feelings for one another until an alien shows up and threatens to destroy the planet.
The Remains of the Day the Earth Stood Still?
(Um, I’ve been trying but I can’t think of any. Sorry.)
I was thinking Amadeus, but I like your answer better.