The first sitcom I really fell in love with as an adult was Cheers. As soon as the opening notes of the theme song played, I was seated and ready to laugh. I later worked at a bar that was specifically designed to look like Cheers. Square bar and all. The entire bar would sit down and watch the show too. 
As evidenced by their later work (and past), the cast was made up of some great actors.
Cast of Cheers: