I never actually watched Andy Griffith Show, but I was (and still am) a big fan of Matlock. His character was great and I was always wondering (and hoping!) he'd finally date the Assistant DA, Julie.
The thing I liked about The Andy Griffith Show was that there was always a lesson in them about the proper way to act. We would use videos of some of the episodes in religion class to demonstrate Commandments. It was a wholesome show, a funny show and a good show. And it seemed that it was genuine Andy Griffith.
Certainly very few actors could boast such an electrifying movie debut as could Griffin in Kazan's "A Face in the Crowd" as manipulative hillbilly Lonesome Rhodes. Compare it with Griffith's Will Stockdale in "No Time For Sargeants" (and if it didn't influence the "Gomer Pyle" series, I'll eat my DVD player!) and you'll have some inkling of his range. I also own an old LP of his songs and routines.