Weird 70s animated sci fi: Fantastic Planet. The original is in French (which I prefer) but it also has an English dub. It's French sci fi from the 70s so this probably goes without saying, but in case anyone was considering a first watch with their parents or small children: there's a fair amount of nudity and sex.

If you haven't seen Wolfwalkers it's also worth a watch. It's by the same studio that made Secret of Kells, and takes place during the Tudor conquest of Ireland. This one is kid friendly, but I've watched it with a group of adults and we all enjoyed it.