On the Jack Benny Show I like the fact that Orson is always introduced with the sound of a gong...funny. He was a good sport, and knew how to poke fun of his image. Of course I suppose he probably needed to at that point in his career.
For my money, probably the best comic performance Welles ever gave was in the Campbell Playhouse program I LOST MY GIRLISH LAUGHTER, where he plays, ironically, a Hollywood mogul who butchers a budding screenwriter's work beyond all recognition. This program is on the Mercury Theatre's web site, although not in very good sound.