Thanks to Todd's comment for the obvious followup to my 20 worst movie sequels. So with no particular number in mind and in no order of horribleness (is that even a word?), I present my list of the worst TV spinoffs:
The Ropers (1979-1980) - Three's company spinoff without Jack and the girls.
Golden Palace (1992-1993) - Golden Girls minus Bea Arthur
Joni Loves Chachi (1982-1983) - Happy Days minus the "Happy"
Joey (2004) - Friends without any friends.
Booker (1989-1990) - Can a horrible show i.e. 21 Jumpstreet have a spinoff? Apparently so.
Baywatch Nights (1995-1996) - As if Baywatch during the day wasn't bad enough
The Lone Gunman (2001) - Could have been as good as the X-Files except for that whole airplane crashing into the WTC plot in the series premiere that came to life a few months later.
A Different World (1987-1993) - Lisa Bonet couldn't cut it here either.
Archie Bunker's Place (1979-1983) - Archie minus Edith
Flo (1980-1981) - Alice's waitress sidekick Flo "Kissing some grits" on her own.
Enos (1980-1981) - Enos from the Dukes of Hazzard minus Daisy.
The Tortelli's (1987) - Cheer's spinoff minus all the characters except for Eddie
AfterMASH (1983-1984) - A decade of Klinger proved to be plenty.
As always feel free to add your own.