My youngest is 8 and oldest is 13.
My 13 year old doesn't really watch many cartoons anymore but I'll let him watch anything that is rated 14 or PG-13 if it's a movie as long as there isn't sexually oriented (I'll use the Notebook as an example).
The only cartoon type shows that I will not allow to be watched that I can think of are the Simpsons, Family Guy, Futurama.....as someone posted they weren't meant for kids but I don't even watch them myself since many kids don't understand that there are animated shows that are geared towards adults. I have never seen a Family Guy episode as a result.
"The farther we go, the more the ultimate explanation recedes from us, and all we have left is faith."
~Vaclav Hlavaty