don’t watch some cartoons if you want to preserve the memory of how fond of the cartoon you were as a kid

I think the best shows are the ones that are just as good as an adult. Avatar the Last Airbender, Gravity Falls, Spongebob before the first movie, Owl House, Phineas and Ferb, and plenty others. If anything, rewatching them as an adult helps you get jokes that went over your head as a kid. Some of those I only watched as an adult, and they were still good.