Krusty Gets Kancelled - S4-E22
Trivia: When this episode aired in Mexico, the name of Luke Perry was translated as - believe it or not - Robert Redford... This was because even though Luke Perry was very popular in that country thanks to 'Beverly Hills 90210', the translator did not know him, and absurdly and stupidly assumed no one else in the country did either, so the name of another 'more popular' celebrity was used.
Krusty Gets Kancelled - S4-E22
Trivia: The scene where Bette Midler sings to Krusty is an allusion to Johnny Carson's penultimate episode as host of The Tonight Show where Midler was his final guest and sang to him.