Avatar: The Last Airbender

Still holds up almost 20 years later. The animation is still so rich and impactful, and perfectly matched to the sound effects. Even the story and jokes hold up like a fine wine. It would make sense to reboot/remake this if it had aged poorly and needed a refresh, but why attempt to mimic perfection? The only acceptable remake I still hope for would be a 1:1 remake with even higher quality animation, but I don't think the industry has any intention of staying true to the original work with all these remakes. If only they might have the original thought of telling a different story inside the avatar universe, instead of trying to re-tell perfection with Aang's story.