He does. He voices Alan Rickman and the Prime Minister in a 2013 episode.
Blinky (not blinkey) is the three-eyed orange fish, who appear in several episodes!
Kang and Kodos
There was a Celebrity Version of Sesame Street's Monster in the Mirror on YouTube. Some of the Sesame Street characters appeared on The Simpsons, including Elmo. There was also a part of one of the christmas episodes of The Simpsons where the Simpsons characters are puppets.
Ringo was the first Beatle to appear in the Simpsons (he was the first major celebrity to appear in the series) in an episode called Brush with Greatness.Paul and Linda McCartney appeared in Lisa the Vegetarian.George appeared in Homer's Barbershop Quartet.
There doesn't appear to be any information to exactly determine which episodes are "famous" but Bart Gets an F is still the highest rated episode (as of 2012)
Matt Groening appears in one of the couch gags at the beginning. He is mentioned in the Episode "That 90's show", but not seen. Groening is seen in the simpsons game though as a big part. Great Question!
Oscar Wilde does not appear in any episodes of The Simpsons. However, a character based on him named Oscar Wilde III appears in "Homer's Phobia" in season 8. He is voiced by John Waters.
There does not appear to be any study of historical writings regarding The Simpsons.
No.
Das Bus
Trilogy of Error.
November 1996.