George Peppard on "Password Plus". The infamous rant, which can be seen on youtube.
Little Richard as a celebrity player on Wheel. Start of the round, spins $5,000, and he guesses "X".
Bill Daily's schtick, while not necessarily obnoxious, was very tiresome and irritating very fast. He was rather dreadful on Match Game, and he once changed a Queen on Card Sharks to an 8, yet he still won the game somehow. He just seemed like an idiotic clown who always tried to force himself to be funny, and he seldom if ever was. That schtick worked on "I Dream of Jeannie", but not in the world of game shows.
Henry Morgan once was very rude to Bennett Cerf. Bennett was in the middle of telling a story while in the process of introducing John Daly, the host, and Morgan made some kind of a rude comment about getting the game started already. Daly handled it well, coming to Cerf's defense in his very eloquent, gentlemanly way. Truly a class act.
Waylen & Madame were indeed obnoxious. I never much cared for puppets on game shows though, or ever for that matter. Part of me also hated that they were in the center square, taking Paul Lynde's place. Squares would probably lasted another 10 years at least if Lynde had stuck around, he WAS that show!
Arte Johnson was another borderline obnoxious celeb. He was okay on "Laugh-In", but not so much so in the game show world.