Oh goodness, that's an interesting question...from my childhood, I'd have to say certain Disney movies. Disney is still a big inspiration for me - one of my dreams is to be a Disney writer, to the point I've drafted up entire rides and movie concepts fitted solely to their style. However, a lot of the Disney movies I remember watching over and over again weren't the typical fan-favorites. I watched Fantasia, Dumbo, Lady and the Tramp, Robin Hood, Winnie the Pooh, and Fox and the Hound a lot...but Lion King and Beauty and the Beast are up there too.
I feel like the cartoons I grew up on when I was really little are split half and half in certain respects of childhood learning necessity - there are cartoons like Powerpuff Girls and Dexter's Lab, where I learned to appreciate comedy, and there are the Hey Arnolds, where I learned to appreciate life. I think Hey Arnold was the biggest cartoon for me because it never tried to talk down to me the way some of the slapstick comedies did. I think that's also why I appreciate the modern cartoon renaissance we're getting with Gravity Falls, Steven Universe, and to a certain extent We Bare Bears and Star vs. the Forces of Evil (more slapstick than the former two but still not purposefully juvenile.) We're still seeing some grossout cartoons like Pickle and Peanut, which have their place even if they aren't my cup of tea, but I feel like the trend is evolving to where cartoons are both speaking to everyone rather than one age group more effectively, and speaking to the kids on a level that meets their true intelligence, rather than what adults think their emotional intelligence is. I liked Inside Out a lot because of that too.
(Sorry for going on a lot there...I just find the social study of cartoons fascinating.)
Because if the universe imploded, we wouldn't be there to enjoy it.