I don't know if this quite qualifies as a cartoon, but the Toy Story movies give me a real kick when I'm blazing. I like to watch Batman the Animated Series or Gargoyles also.
Spongebob, Rockos Modern Life and Ren and Stimpy are all pretty good while baked. Some others i dig are Fosters Home, Fairly Odd Parents and Scooby Doo. Also He-Man, Gi Joe and Thundercats too but thats for pure nostalgic purposes, they take me back to my happy place.
Every cartoon is awesome when you are high ... from what I have heard. The animated scenes in "Pink Floyd's The Wall" look pretty good when you are high.