2. 'The Simpsons'
The Simpsons first hit the air in the late 1980s, and it continues to this day, but it clearly reached a creative peak in the 1990s. It was a time when creative geniuses like Conan O'Brien, James L. Brooks, John Swartzwelder, Greg Daniels and many, many others came together to flesh out the vision of creator Matt Groening and make it one of the most brilliant shows in the history of television. Fans will forever dispute when exactly the quality began to dip, but it's hard to find a bad episode in seasons three through six. As time goes by, they only get funnier and funnier. One day Fox will finally pull the plug on the show and many will claim it as an act of mercy, but we'll be living in a worse world once new episodes of The Simpsons stop airing.