The Andy Griffith Show old reruns still crack me up more than any other. Just the B & W shows before Don Knotts left, though. Not the shows after they went to color.
Absolutely "yes" to the Don Knotts observations. I don't think I watched it much after he left. He was a comedic genius, I thought. It didn't hurt that the show's writers knew exactly how his character should be portrayed. And he pulled it off beautifully, imho.