6. The Simpsons, Season 1 (Fox; December 17, 1989 - May 13, 1990)
A common complaint against the first season of The Simpsons was (and still is) how inferior and cheap the early animation looked next to the more mature renderings of later seasons, which is certainly true. Still, there were other issues that held The Simpsons back in its infancy.
Early on, Homer and Bart were far rougher around the edges—Homer with his quick anger and Bart with his troublemaking. The writers toned down these aspects as the series went on and focused on the lovable stupidity of both characters. The town of Springfield would grow to be one of the most richly populated in television history, but at the beginning, the landscape felt sparse, as the dozens of Sprinfield residents we would come to know and love were mere sketches of what they would become.
Sure, these complaints are similar to those that one would have about any show, but when something continues on as long as The Simpsons has, those nitpicks come into fuller view.