#1 The Simpsons. Let's see. I've already called the past 20 years of animation The Simpsons era, already said that Futurama doesn't make the list because it doesn't match up with Matt Groening's best work. I've listed six out of the top seven, but I haven't listed The Simpsons yet. I wonder what cartoon is number one on my list?
In the past 20 years, many cartoons have come and gone. Some have come and sweet merciful Jesus I wish they would go already. Ren and Stimpy, Beavis and Butthead, King of the Hill are in the Come and Gone category. South Park and Family Guy are in the Please Leave Now category. Some of these I just don't care for that much. Others I actively dislike.
And then there's The Simpsons. Unlike many of the other shows on this list, I don't feel like I have to explain to the uninitiated why the show is good. You already have your own opinion about The Simpsons. I don't believe that every one of the 400+ episodes is brilliant work of art, but a lot of them are, from some of the earliest shows to the some of the most recent. I never miss a Simpsons Halloween special.
I like some of the shows on the list because of superior voice talent. Others are on the list because of the writing. The Simpsons is there for both. The regular cast is brilliant and the guest star list is the most impressive in television history. The depth chart for the cast of characters is Dickensian. The Simpsons has more interesting characters that the show has killed off than most shows have interesting characters. There is hardly a single cultural milestone of the past twenty years that the show hasn't commented on.
While I could compile a list of favorite lines from the show, let me finish my recommendation with the line of dialog that explains the main comedy source of the show, the relationship between Homer and Bart.
"I've threatened you, I've beaten you. God forgive me, I've even tried reasoning with you."