The fourth season (1975-1976) of "The Bob Newhart Show" is right up there with the second season, and perhaps even a bit better. Some of the funniest episodes from the fan polls are from this season, and while there are perhaps a few fewer recognizable faces as guest stars, you will still see a few. The writers and cast by this point have both hit their stride, and the chemistry is phenomenal.
The Season is book-ended by appearances by Tom Poston as The Peeper, Bob's college buddy whom Emily can't stand. Of course, Tom would go on to be a regular in Bob's next sitcom "Newhart", and then there is the irony that Tom and Suzanne Pleshette would eventually get married. In-between, there are many events, including the death of Mr. Gianelli ("Death of a Fruitman"), Carol gets married ("Carol's Wedding"), Bob hosts an arrogant French psychologist ("Shrinks Across The Sea"), Bob forms a short-lived partnership with another psychiatrist ("Seemed Like a Good Idea At the Time") and many more.
Two of the funniest episodes ever are in this season with "Who Is Mr. X?", where Bob is ambushed by a morning talk-show host and is so flustered he reveals that one of his patients is a public servant. The other classic is "Over the River and Through the Woods", in which Bob gets out of a trip to Seattle over Thanksgiving by claiming that his patients need him. He ends up hosting a party with Jerry, Howard, and Mr. Carlin in which they all drink too much watching William and Mary's worst college football defeat, and make the funniest call for Chinese food ever recorded. I also very much like "Bob Has To Have His Tonsils Out, So He Spends Christmas Eve In The Hospital", and the title explains the plot to that one.
All in all, there are 24 episodes on three 2-sided DVDs, just the same as the first three seasons. Also like seasons 2 and 3, there are five episodes with commentary, but I have to say that the commentary has improved this season; perhaps because they have more people participating in them. I would still not call them great commentaries, but they are significantly better than the prior seasons. There is a short season 4 feature, and there is also a gag reel. In all, this is probably the best set of features they have included, but more importantly this is the season with the funniest episodes.