Quotes are fun but one of the limitations of quotes when it comes to TAGS is
that the comedy of the show, particularly Barney's style, is primarily
visual.  Don Knotts was a master of visual comedy.  Obviously, quotes can't
capture his actions and expressions.  Having said that I wish to submit a
sampling of some of my favorite "visual humor" moments of Barney...

1. Scampering around on the floor of Weaver's store, thinking there was a
   shoplifter in there, being startled by talking toys, etc.
2. When he was supposed to board the gold truck in a "split second"
   stumbling, falling, bumbling and taking forever.
3. When he was drunk because Otis spiked the water cooler and Andy was trying
   to walk him to the door staggering, walking the wrong direction, etc. ("Bless
   his heart").
4. When he had accidently fallen on the criminal (given him the old "body
   block") and the confused expression on his face as the guy struggles to get
   out from under him.)
5. His expressions whenever someone's praising him or inflating his ego. (I
   use the same expressions for laughs sometimes on appropriate occasions.  Many
   people have said when I do it, "You make me think of Barney Fife.")
6. Whenever he's arresting someone such as Otis in front of someone he's
   trying to impress, marching them to the cell, barking out orders ("This is a
   prison not a HOtel!").
7. His gun going off and his facial expression whenever his gun goes off.
8. Whenever he almost gets hit by a car.
9. Whenever he shuts the cell door on himself.