Reminder that The Principal and the pauper didn't kill the Simpsons, not really. That episode was produced by Oakley-Weinstein, the characterizations, good humor, etc. were still intact, "classic" in that episode and not yet full retard.

Sure, the plot of Skinner being an impostor was silly, but that episode didn't have things like Homer being treated as the centre of the universe, Mr. Burns being a friendly senile buffoon, springs bouncing a ship back and forth, and a Super Bowl adventure filled with unfunny guest stars.

It's Mike Scully who killed the Simpsons. If you want episodes that truly signified the downfall of the show, these are more fitting picks:
>When you dish upon a star
>Kidney trouble
>Sunday cruddy sunday
>Monty can't buy me love
>The old man and the c student (this is the one that actually destroyed Skinner's character. He gave Bart of all people a showcase, which is unusually dim for his character, and later punches Homer in the face for what Bart did, which is retarded and out of character)

These episodes were the true point of no return.