Mary Kay and Johnny began broadcasting in 1947, and is widely considered to be the first sitcom. It also holds the distinction of being the first television show to depict a couple sharing a bed. This is a fairly big deal considering the bedrooms of famous TV couples for years afterward—the Ricardos on I Love Lucy (1951-57), the Cleavers on Leave it to Beaver (1957-63)—slept in twin beds.
22. Mary Kay and Johnny Stearns on Mary Kay and Johnny