I went to full geek mode to research this. My materials are a few years old, so I may have missed a couple.
In the 54 years since the networks started prime time programming, I found a total of 16 hour-long series that were described as situation comedies. As for how successful they were, you can judge for yourself.
Aloha Paradise (ABC, 1981) Love Boat on a tropical resort.
Breaking Away (ABC, 1981) Adapted from the movie.
Enos (CBS, 1980-1981) Spinoff from the Dukes of Hazzard.
Going My Way (ABC, 1962-1963) Adapted from the Bing Crosby movie.
Good and Evil (ABC, 1991) Two sisters, one good, the other evil.
Harts of the West (CBS, 1994) Beau Bridges leaves the big city to become a cowboy.
Husbands Wives and Lovers (CBS, 1978) The lives of five suburban couples.
It’s a Man’s World (NBC, 1962-1963) Four guys on a houseboat
The Last Precinct (ABC, 1986) Adam West commands the worst police officers in Los Angeles.
Lobo/Misadventures of Sheriff Lobo (NBC, 1979-1981) Slow-witted, bumbling country sheriff.
Love American Style (ABC, 1969-1974) and Love Boat (ABC, 1977-1986) We can debate whether these two shows fit the classic definition of situation comedies (and I agree with Walloon that LAS doesn’t), but they are the two most successful series in the entire genre.
Lucy-Desi Comedy Hour (CBS, 1957-1967) Not really a series, it was a collection of specials that were brought together starting in 1962, and run as a summer replacement for several years.
Stir Crazy (CBS, 1985-1986) Adapted from the movie.
That’s Life (ABC 1968-1969) Young couple meets, falls in love and marries, also sings and dances. Maybe not really a sitcom, more like a collection of skteches with a common theme.
When the Whistle Blows (ABC, 1980) A bunch of guys do construction work and hang out at a bar.
When you consider that ABC, CBS and NBC have been filling seven nights a week for more than a half-century, then add DuMont, Fox, UPN and WB, the broadcast networks have collectively run something like TWO MILLION HOURS OF PRIME TIME PROGRAMS. Yet, hour-long sitcoms in total have aired less than the newsmagazine 60 Minutes. This has been a spectacularly unsucessful programming style for the networks.