Andy jumped the shark as soon as it went color. Which coincidentally, was when Don Knotts left. The show was never the same after that. When I watch it at night, if I see it's an episode filmed in color, I usually pass it up. I really didn't care for Howard too much. The corniest episode is when he got a "bachelor" apartment. I cringe when they show that one.
My favorite episode is when Andy gets the English butler----the guy who played Dr. Bombay on BEWITCHED. Opie asking for bubble and squeak and saying cheerio to Aunt Bea is priceless.