Tim Conway, Breakmaster

The old Carol Burnett Show used to have two tapings for each episode.  During the first taping, all of the sketches were played straight; in the second taping, the actors were allowed to be looser with the material and free to improvise.  While this method was used for (I believe) the entirety of the show's 11-season run, I have to believe that the number of the 'improv show' sketches that made it onto the air skyrocketed dramatically after Tim Conway joined the cast.  Easily one of the funniest actors in TV history, Conway was famous for coming up with new gags and improvised lines that destroyed not only the audience, but clearly his co-stars as well.

I could easily fill this post simply with clips of Conway cracking up Harvey Korman, and those are well worth searching out in your own time.  Yet Conway's most famous improv occurred in a Korman-less skit, as his on-the-spot creation of a pair of elephant anecdotes not only brought a Mama's Family sketch to a virtual halt, it also set up one of the single biggest punchlines of all time, courtesy of Vicki Lawrence.  Boy, do I love everyone's facial reactions here --- you have Lawrence trying to best to hide a smile, Dick Van Dyke gamely looking down but openly grinning like a fool, Conway actually even cracking himself up out of pleasure at how well he's killing and Carol Burnett instantly realizing Conway is going off-book and is about to unleash something hilarious, yet trying to keep as much of a straight face as possible.