I always thought that he should have been one of the finalist to take over for Johnny Carson. Too bad his humor has been absent these past few years. RIP
I remember seeing an interview with him many years ago (probably late 70s/early 80s.) He was offered his own talk show, but absolutely refused to compete in the same time slot as Johnny Carson because he felt he owed his career to Carson, and it would be an act of betrayal to compete against him.