I see a lot of 80's first-run syndicated crap there, especially garbage that had stakes put through their hearts by networks only to be resurrected as local TV station time slot filler. Mama's Family and Charles in Charge, for instance. Hackwork churned out on the cheap with flailing and mugging in lieu of actual acting, sets that looked like they were about to fall over at any second and bargain basement production values that made small town public access cable look polished and competent.
She's the Sherriff, What A Dummy!, Small Wonder of course, low-rent revamps like The Munsters Today, The New Gidget, The New WKRP in Cincinnati - a parade of loathsomeness.
I'm not surprised to see Homeboys in Outer Space there either. Cheap, tacky, "actors" who hammed it up intolerably and they seemed to have stolen Married With Children's laughtrack, especially the "Ooooooooooooooooh!" Hell, you could have filled this list up with UPN and WB's various comedy failures over the years, a collection of two-season time fillers, six-episodes-and-out losers and total bombs on which the plug could not have been pulled fast enough.
Why confine the list to American sitcoms? Somebody mentioned My Hero, yeah the list of horrible UK sitcoms could go on and on and on. Canadian sitcoms too. There are not enough hours in the day to list them all.