I've decided to rank the five appearances of Ernest T Bass from Greatest to least. (As for Return to Mayberry that's for a separate list)

1. My Fair Ernest T. Bass
A Classic episode full of humor as well as showing that even the wildest of men can find love. I think George Bernard Shaw would have liked this one over My Fair Lady

2. Ernest T Bass joins the Army
Having Andy and Barney deal with a wild Mountain Man is truly hilarious. Ernest T Bass's physical is also a very funny.

3. Mountain Wedding
The first time we meet Ernest T Bass. As first appearances go, it was pretty good, but Bass seemed a bit too calm.

4. The Education of Ernest T Bass
Not as funny as the previous episodes as well as being ridiculous (Why would Andy want to enroll Bass in a Fifth grade class instead of sending him to Night School?) Also Helen Crump was not a character that should have been put in an episode with Ernest T. Bass Unlike the The Darlings, The Army Sergeant, or Mrs. Wylie, Helen can't do comic anger.

5. Malcolm at the Crossroads
One Word: Awful. Harvey Bullock (who in my opinion was one of the greatest writers to work on the show) just couldn't write Bass the way Jim Fritzell and Everette Greenbaum could. Not helping is Barney's absence from the episode. Part of what made Ernest T Bass funny was Barney reacting to him. With hime gone, the episode just is not funny

The last one was awful. I'd say Mountain Wedding was good and the other three were gold. It's amazing how he became legendary in four appearances.

My fair Ernest T. Bass was the best one. "How do you do Miss Wiiiiiileeeey.." Bass would often complain about his love life or lack thereof, but here he got the best looking girl at the dance, Rowena (I love dark haired, dark eyes women so I would honestly gravitate to her), and they ran off together to parts unknown. I love you Ken Berry, but you were an idiot to divorce Jackie, unless she was a ball breaker (and maybe she was, who knows).

A lot of these smaller communities have their snooty upper class folk and class differences was actually a subtle feature of the series (Mayor Stoner, the snooty wench who did not want Raif Hollister to sing his number, the first mayor who wanted to kick that eccentric old man off his property for back taxes, to the old shopkeeper from the first season Christmas episode, to Mrs. Wiley and her "socials" for "respectable folk". Poor Andy had to be the go between between the rich folks and the common folks.

The Mountain Wedding is a close second, and I think anyone who watched that episode for the first time couldnt help but crack up at this. That silly song Bass sang in the bushes, some songs with The Dillards and Barney Fife in a wedding dress.

The Army episode was OK, Alvin Melvin was in this one. Rare sighting of a black person (a black recruit in the line) in the series. What would have made a funnier show if Bass did his physical and had to deal with the military doctors and Bass not following instruction to comedic effect, Bass with a psychatrist would have been funny with the right person (Don Rickles!), having the pyche doctor declare him mentally ill and Bass throwing bricks and running back to the hills.

I wont watch the Helen Crump one, because it is Helen being mad (actually rightfully so), Bass is annoying here and so on. The last episode I do not remember, maybe I can catch it on YouTube tonight. But, I do not watch the color episodes unless Don Knotts is in them

I like Bernard Fox, so the Malcolm episode I didn't find to be "awful." I might still rank it last though, because the others were good.

The army episode I haven't seen in a while, but I would rank it #4 from what I recall, following My Fair, Mtn. Wedding, and Education. So I think I'm in closer agreement with Yong Fang than the original poster's rankings.

The last one was awful. I'd say Mountain Wedding was good and the other three were gold. It's amazing how he became legendary in four appearances.

It will take me a little time to decide on a ranking, but... only five appearances!

Truly an iconic character to have such a small number of stories about him.