Not every cartoon fanbase is shallow or close minded. These are cartoons that do have respecting fans so they can tolerate other opinions and aren't disrespectful either. If there's any I missed feel free to add them.
The Top Ten
1CatdogCatDog is an American animated television series created by Peter Hannan for Nickelodeon. The series depicts the life of conjoined brothers, with one half being a cat and the other a dog.
Probably the most patient and not perverted cartoon fanbase I've encountered.
2Gravity FallsGravity Falls is an American animated television series produced by Disney Television Animation that first aired on Disney Channel, and then on Disney XD from June 15, 2012 to February 15, 2016. The series follows the adventures of Dipper Pines and his twin sister Mabel in the fictional town of Gravity ...read more.
This had to be somewhere in the top three in all honesty.
3Codename: Kids Next Door
Better and less disgusting then lots of other cartoon fanbases.
4Danny PhantomDanny Phantom is an American animated series created by Butch Hartman for Nickelodeon. It was produced by Billionfold Studios and distributed in Canada by Nelvana, a Canadian animation company. The series follows a teenage boy who, after an accident with an unpredictable portal between the human world ...read more.
No explanation required at most.
5Rick & MortyRick and Morty is an American adult animated science fiction sitcom created by Justin Roiland and Dan Harmon for Adult Swim.
Ignoring the cringe musically's, the Rick and Morty fanbase seems to be a very good yet intelligent fanbase.
6Invader ZIMInvader Zim is an American animated television series created by Jhonen Vasquez for Nickelodeon. The series centers on an extraterrestrial named Zim from the planet Irk, and his mission to conquer Earth and enslave the human race along with his malfunctioning robot servant GIR.
A very loyal yet honest fanbase.
7Samurai JackSamurai Jack is an American action-adventure chanbara animated series created by Genndy Tartakovsky for Cartoon Network. The series premiered on August 10, 2001, with a TV movie called The Premiere Movie, before ending in its fourth season on September 25, 2004, without concluding the story. A revival ...read more.
Again a very respectful yet decent fanbase.
8Avatar: The Last AirbenderAvatar: The Last Airbender is an American animated television series that aired for three seasons on Nickelodeon from 2005 to 2008. Avatar: The Last Airbender is set in an Asiatic-like world in which some people are able to manipulate the classical elements by use of psychokinetic variants of Chinese ...read more.
Pretty decent fanbase from what I've seen, however I'd recommend avoiding the disgusting garbage from Deviantart.
9Rocko's Modern LifeRocko's Modern Life is an American animated television series created by Joe Murray for Nickelodeon. The series centers on the surreal life of an anthropomorphic Australian-immigrant wallaby named Rocko as well as his friends: the gluttonous steer Heffer, the neurotic turtle Filburt, and Rocko's faithful ...read more.
Self explanatory at most.
10Hey ArnoldHey Arnold! is an American animated television series created by Craig Bartlett that aired on Nickelodeon from October 7, 1996 to June 8, 2004. The show centers on a fourth grader named Arnold, who lives with his grandparents in an inner-city boarding house.
From what I've seen the fans of this show seem to tolerate other opinions/ views very well.