Kinda surprising that one of the most popular series of the '60's hasn't been mentioned on this board.
It was entertaining during its first few seasons (especially the B&W episodes), but in later years, the writers had increasing difficulty in coming up with fresh stories. Of course, that's true of all TV shows.
But what really bugs me is the character of Milburn Drysdale. Early in the series, he was an even-tempered avuncular man who went overboard to help the Clampetts settle into their new lifestyle. But later, after the Clampetts' fortune greatly increased, he became a virtual madman, absolutely obsessed with money! The victim of his abuse was poor Jane Hathaway! You'd think that with her experience and expertise, she'd get a better job with a better employer!
Of Paul Henning's "rural" comedies, IMHO, THE BEVERLY HILLBILLIES was the best, followed by PETTICOAT JUNCTION. GREEN ACRES was the absolute pits! I did watch THE REAL McCOYS as a kid, but to tell the truth, my memory of that show is quite faulty.
When The Beverly Hillbillies premiered it was the talk of the school (I was in High School). The only show I remember being more of a "must watch" was Batman. I agree the earlier shows were funnier, which I think is often the case with comedies. But I did enjoy Drysdale's evolution into a greedy madman. Remember "Super Banker"?
Granny was my favorite character, she always scored with the LOL humor.
As for Jane, I imagine she stuck around to be close to Jethro.
Mrs. Drysdale never changed. In fact, she was the stereotype of the social climbing, elitist snob. Makes me wonder if there were real-life women like her, especially during the Gilded Age of the late 19th-early 20th century. I'm thinking of the Vanderbilts, the Rockefellers, the Whitneys, etc.
In the last season, Granny herself has become insane, believing that Navy frogmen (including Elly's beau) actually become real frogs once they hit the water. There have been a number of episodes on this theme, and I wish it would be resolved already! Well, at least they're better than those wit Phil Silvers (whom I've always loathed).