1. We'll Really Miss You Mrs. K (Season 25, Episode 3 - Four Regrettings And A Funeral)
This episode aired on November 3, 2013, just 9 days after the untimely death of the show's voice actress Marcia Wallace, who provided the voice for Bart's teacher Edna Krabappel. As a touching tribute to Wallace, the chalkboard gag didn't even try for laughs and just left a simple yet poignant single "We'll really miss you Mrs. K." while Bart looked on with a profound sadness. Anyone who thinks that The Simpsons wasn't capable of tender emotion anymore needs to check this brief yet wonderfully affecting moment out. It also might be the best use of the chalkboard gag to date. Superb. Which Simpsons chalkboard gags are your absolute favourite over the course of the show? Shout them out in the comments!