The Bob Newhart Show 19th Anniversary Special, on CBS
IMDb; TV.com; Wikipedia

This was a reunion special based on the 1972-78 series "The Bob Newhart Show," which I never saw. It aired in November 1991, about a year and a half after the end of the 1982-90 series Newhart, of which I was a fan. Both series, of course, starred Bob Newhart, though he played different characters in each. Anyway, I'm sure I watched this special, in spite of not really knowing anything about the original series. And I'm sure I found it amusing, though I don't remember anything specific about it, now. (I'm making this little page in February 2017, having remembered the special when I was working on my website's calendar for March, and saw that next month the final season of "Newhart" is being released on DVD.) So, I don't know what to tell you, except that basically the special is just like a new episode of "The Bob Newhart Show" (except it was an hour long instead of the usual half hour). And... while I don't remember specifics, I do remember the premise of the episode, which I quite liked. I just can't tell you what the premise was, because it would totally spoil... something else. But I wanted to at least mention the special, even if I can't tell you much about it.