I believe one of the most underappreciated classic TV series is Hogan's Heroes (1965-1971). It had clever story plots and a very talented comedic cast. The pilot episode was slightly different than the rest of the six seasons of the series, which is often the case in television, but it's a good representation of what the basic structure of each episode in the future was going to be like.
At times Hogan's Heroes can seem absurdly unrealistic. I think that is part of the charm the show has. Senior POW officer Col. Robert Hogan (Bob Crane) and his group of fellow Allied POW soldiers could have easily taken over Stalag 13 or escaped en masse at any time but they didn't. Their special operations group specialized in infiltration and sabotage. Being war prisoners gave them cover and plausible deniability. Of course, the effects of being successful and expert at what they did couldn't be ignored by the Axis side. Several episodes during the series addressed the large number of sabotage events in the area surrounding the POW camp. The Germans would investigate but by the end of those episodes everything would return to the status quo.
Rather than fighting with guns and bombs (most of the time) the characters of Hogan's Heroes practiced Sun Tzu's principle of war, "subdue the enemy without fighting."
Often the preferred tool was social engineering. Talking their way out of trouble. Turning their enemy's assets and resources against themselves. Manipulating the POW camp Kommandant Col. Klink (Werner Klemperer) into thinking a plan was his idea.
My personal favorite scenes tend to be when someone from the Third Reich gets discredited. By their nature Nazis will turn on each other quickly. If that isn't karma then I don't know what karma is.