Mirror Image
There was a certain episode where Jean Stapleton played TWO characters: Edith, and the girlfriend of a butcher who was madly in love with Edith, and who found this girlfriend who looks identical but with drastically different personalities.
Another Ride
Carol O’Connor once suggested a revival of All in the Family where Archie drives a cab full time and depicts his interesting interactions with passengers. However Norman Lear did not take to the idea at all and focused on other works.