Since there's an american comics thread (which is dead), why not make one for cartoons? I love cartoons (I don't have much of a life >_< ), usually because they can get away with things that can kill you in real life.
Here's some of my favorites:
Super Mario World (I remember waking up at 6 in the morning just to see it when I was little)
The Grim Adventures of Billy and Mandy
Ed, Edd, n' Eddy
Batman Beyond (it's what actually got me into Batman)
Justice League Unlimited