At some point during its 14-year run, The Simpsons turned into one of the best sitcoms on television—and that's not a compliment. At one time, to call The Simpsons the best show on Fox would have been a vast understatement; to say it was the best sitcom on television would have been inadequate; and to describe it as the greatest TV show in history would (and still does) minimize its importance by limiting its cultural impact to the small screen. Who knows when it happened—maybe it was when Homer visited the leprechaun jockeys in Season 11, or when he was...