I may be in the minority, but I was never much of a fan of Andy Griffith. I liked My Three Sons though, but the episodes I saw in the '70s were seasons 6-11, so I guess I'm more familiar with those. I've only seen a handful of B&W episodes.
You are correct about the first two seasons of Petticoat Junction. For some reason those were never syndicated. TVLand aired a few of them, and I believe both seasons are available on DVD.