9. This Is Not A Clue...Or Is It? / I Will Not Complain About The Solution When I Hear It (Season 6, Episode 25 & Season 7 Episode 1 - Who Shot Mr. Burns?)
This is a two-parter for one of the most brilliantly memorable pairs of episodes in the show's history, the famous Who Shot Mr. Burns? saga. The first chalkboard gag just aims to screw with viewers who knew what was coming, and anticipating the inevitable s***storm when it was revealed that Maggie Simpson was the shooter, the writers decided to temper it slightly by politely asking viewers not to flip their lids at the revelation (which, whoever it was, would surely have incited fan anger anyway).