Here's another great multi-movie collection offered cheap from Disney. You get:
The Apple Dumpling Gang (1975) Bill Bixby is actually the star of this one, but Don Knotts and Tim Conway as a pair of bumbling thieves were SO FUNNY that the two actors continued their partnership outside of Disney
Gus (1976) Knotts is the lead but this movie is packed with Disney actors (even Bob Crane). Collectible for the fact this is considered the worst live-action ever put out by Disney.
Hot Lead and Cold Feet (1978) This western is a surprisingly funny gem for the few who have actually seen it
The Apple Dumpling Gang Rides Again (1979) Don Knotts and Tim Conway are the leads in this sequel where the two land in a variety of Laurel & Hardy-type situations.
If you really want to "get Knotty," search for another Don Knotts box set called "Don Knotts Reluctant Hero Pack," which is just $14.99 at Amazon for another four movies.