These famous guest stars were on the show, in appearance order:

Larry Miller, Megan Ward, David Schwimmer (twice), Julia Louis-Dreyfus, Illeana Douglas, Brooke Langton (twice), Conan O'Brien, George Plimpton, Marie Osmond, Paula Abdul, Amanda Peet, Peter Boyle (twice), Mariska Hargitay (three), Rodney Dangerfield, Maureen McCormick, Davy Jones, Wendie Malick, Al Roker, Jenna Elfman, Molly Shannon, Jonathan Lipnicki, Don Rickles, Jason Alexander, Andy Dick, Amy Yasbeck, Kristin Davis, and also Rick Overton.