In this interesting and quirky episode, Sam fakes impotence to befriend a psychiatrist that Lilith and Frasier introduce him to. Her introduction was quirky enough, given the smart and silly conversation she has with Frasier and Lilith. But Sam goes to great lengths to seduce the woman. Most of his attempts are dashed right away by Dr. Rydell.
So Sam has to get creative. When he converses with the gang, the idea of impotence pops up. Sam sees this as a perfect opportunity for him to appear vulnerable and in need of the great doctor's help. So he makes an appointment with her to discuss his problem.
This scene is the payoff of the episode, so wonderfully done by Ted Danson and guest Madolyn Smith-Osborne (as Dr. Rydell). Often the conversation flirts with hysteria yet somehow provides a subtle amount of tension as we wonder who will win this battle of wits and dialogue. Danson likes to act with his face as much as his dialogue. It is a joy to watch his facial expressions change from discomfort to disgust to lust in matters of instances, perfectly supplementing his often tangent dialogue. Smith-Osborne is just as convincing combining her superiority with her vulnerability -- providing just the right combination of slyness and innocence. This is a very difficult scene comedically, and both pull it off with a fascinating effortlessness. Kudos.
While amusing, much of the rest of the episode is forgettable. I was, however, pleased with the final conversation between Rebecca and Sam. I think we get a bigger sense of Sam's vulnerability, which makes him that much more likable. Almost a tragic (almost) comedic figure. This is what makes Cheers so great. It's a story that places comedy above the lessons -- but it places the lessons in there to make the situation more realistic. Cheers is a fascinating comedy because it adds the humanity to the characters -- not in a wishy-washy manner like Friends (e.g.) -- but in a tempered manner. No show has been like it since.
While far from the best episode of the series (or even the season), "What's Up, Doc?" is still a successful effort.