CNN made an effort at a quiz show some time ago and Anderson Cooper was the emcee. I think he has a lot of potential.
In office run-thrus, Dick Martin seemed like he could handle Mindreaders. Once he got in the studio, though, he seemed a little overwhelmed and the "deer-in-the-headlights" came out a little bit.
As I think back, Dick Gautier and Greg Morris should have at least done an office run-thru of something. We discovered Pat Sajak who did the Puzzlers pilot. Bobby Van turned out to be pretty good on Showoffs and Make Me Laugh. We never tried out Nipsey Russell and probably should have. Geoff Edwards eluded us but eventually did a pilot.
Jim Perry emceed an office run-thru of Puzzlers IIRC but was never up for the job. He just came in to do the office run-thru. Several names were tossed around for Blockbusters, including Jack Clark, but Ira Skutch wanted Bill Cullen. Jack Narz would have been good on Blockbusters but was never given a shot. I'm sure he would have welcomed the work.