I'll concur with Dan (the Man) about "Designing Women" up to the point where Delta Burke was forced to leave the show.
It never recovered. Delta was, IMO, the heart and soul of the show because she was based on the show's creator, Linda Bloodworth Thomason. And it's no suprise to me that it was Bloodworth Thomason who made it impossible for Burke to continue even though Burke had some of the finest moments network TV comedy has ever seen.
There have been several different stories told about what went on behind the scenes of that show. Everything changed, apparently, when Burke began putting on weight. Some of the best shows in that series had to do with how "Suzanne" -- a former beauty queen who was truly a beautiful woman -- dealt with reactions to her weight. In many ways, the character was a caricature of a typical southern beauty, but Burke was the equal of Bloodworth Thomason's intent and revealed Suzanne to be a deeper soul than was apparent on the surface. Other cast members have not supported Burke's more vivid accounts of what happened on the set, but they also have not been wholly open about it, either. Whatever happened, I have to say I cannot for the life of me figure out what's holding up the release of all the seasons of the show on DVD.