The Simpsons: 15 Modern Episodes You Need To Watch

"The rat symbolises obviousness" - Ralph Wiggum

In one line, The Simpsons writers delivered perhaps the most scathing putdown of Oscar winning movie The Departed, and its less than subtle use of symbolism. That's not the only highlight of the episode though, as the whole thing is an inspired send up of Martin Scorsese's crime drama.

A new kid at school, Donny, quickly forms a close friendship with Bart. However, it turns out that Donny is actually a secret agent working with Principal Skinner and Superintendent Chalmers to bring down Bart's criminal empire. The episode gets plenty of mileage out of spoofing the film, but the relationship between Donny and Bart really works here, especially as Donny desperately tries to conceal his true identity from his new friend.