“Some TV shows, like Three’s Company, had the same plot every show.”
The Dick Van Dyke Show had the same plot for every episode: Laura Petrie was foolishly jealous of her husband Rob Petrie for foolish reasons and gives Rob the cold shoulder, Rob freaks out, but eventually Laura realizes she was foolish, and they make up by the end of the show.
Accept for the invasion of the body snatcher parody, I was a kid when I saw that scared me to death.