By default, and also my all time favorite show, will be Cheers.
I have the entire collection on DVD. Got my son to fall in love with it too. Started watching it in high school. Got instantly hooked. Rarely a collection of such fine talent and direction in at least that time era. Loved it so much I actually took a trip to Boston to visit the Famous Bull and Finch pub. The real bar that the sitcom was depicting is in real life extremely small in comparison to the set. All the features are there like the rear pool room and restaurant upstairs.
That was a fantastic trip. One I didn't mind paying $12 for a cheeseburger and a beer. Mind you that was in the early 90's. Today that's like a $20 bill. But I got to see the pics of the celebs on the wall, buy some gift shop stuff and always have that memory of drinking a beer at Boston's Cheers!
Seinfeld was ok. A show about nothing can only go so far.