The Daily News has put together some pages on talk shows and which guests have appeared most often on which shows over the years. Alas, they derive their raw data from the Internet Movie Database, which is woefully incomplete on this kind of information. Carl Reiner was one of Johnny Carson's most frequent guests but he ain't anywhere to be seen on the Carson list. Pete Barbutti was on with Johnny over seventy times but they only have him down for fourteen.
They also have Johnny down as a guest on the show fourteen times and there's no way that's right. He hosted it for thirty years but guested zero times. (He did do one cameo walk-on one night when David Steinberg hosted.)
There are also silly mistakes like this one: They list as David Letterman's most frequent guest on his NBC Late Night show, George Miller. They say he was on seventeen times and they describe him thusly: "George Miller was born on March 3, 1945 in Chinchilla, Queensland, Australia as George Miliotis. He is a producer and writer, known for Mad Max: Fury Road (2015), Happy Feet (2006) and Mad Max (1979). He has been married to Margaret Sixel since 1995. They have two children. He was previously married to Sandy Gore."
That's George Miller the director they're talking about and they have a photo of him. The George Miller who was on with Dave was George Miller the stand-up comedian and he was on a lot more than seventeen times.
The project was a worthy one but it's one of those "garbage in, garbage out" situations and I'm not sure the full data they'd need to do it right even exists. Still, it's nice to be reminded of some of the people who were on those shows, way back when.