Being a kid who grew up with Charlie Brown, this episode owns me. 
Any other AD contenders as I course through the rest?
I think The Immaculate Election and Sword of Destiny are just as funny.
I nominate Afternoon Delight, not least because of Gob’s anti-sexual harrassment speech, which had more bleeps than a David Mamet film on network TV. His finest hour.
I agree that Afternoon Delight might take the cake. The first episode of S3 was also sublime.
–Cliffy