Oddly, when I finished my post on WKRP In Cincinnati, two fortuities emerged. 1) I could think of no truly great sitcoms in the last three decades, and 2) I rounded out my list at an even 10, with all of them beginning in the 1970s or earlier, and 7 of the 10 representing the Golden Age of the 1970s.
In thinking over the last 3 decades, there were some good sitcoms: Night Court, Cheers, and Seinfeld are the three most well known 'choices.' But Night Court was Barney Miller Lite, Cheers, like M*A*S*H*, ran too long, and, frankly, I think Ted Danson's other sitcom, Becker, was actually better written and acted, and Seinfeld failed for two reasons: first, it was really an inferior version of the old 1950s sitcom, The Abbott And Costello Show, and two, one never really cared about the characters. Add to that the fact that for every memorable Soup Nazi episode there were three or four simply bad episodes and a bevy of rather generic episodes.
I then thought of Married....With Children, and was tempted to name it, for it was the best example of a slob comedy around. It was vulgar, anarchic, disrespectful, and very funny. But, it also ran too long and, despite sexy Kelly Bundy, also fell into banality in later seasons. But, it was far better than pretentious crap like fellow slob comedy Roseanne.
Then there was Home Improvement, Everybody Loves Raymond, 30 Rock, The Office, Scrubs, but every episode I've seen of those shows mark them as utterly generic and non-innovative. Of course, innovation gets harder as time wends onward. And don't even get me started on the crap that was The Cosby Show and its spinoffs.
Two exceptions have been The Simpsons and, even more so, Family Guy. Unfortunately, they are both more properly satires and cartoons, not really sitcoms. Besides, The Simpsons long ago Jumped The Shark.