Complex sentence: "The Principal and the Pauper" is one of, if not the most controversial episode of the show, many fans and critics have reacted negatively to the revelation that Principal Skinner, a recurring character since the first season, was an impostor.
Split into simpler sentences: The Principal and the Pauper is one of the most controversial episodes of "The Simpsons". Many fans and critics reacted negatively to the revelation that Principal Skinner, a recurring character since the first season, was an impostor.