The NeverEnding Story!! It's so lame and 80s, I love it so much! Listen to this banger of a theme song! But it's actually got a really good story with quite meaningful underlying themes (self-discovery, depression, the importance of creativity and how our school system is destroying it). Unfortunately it seems to be relatively unknown, possibly because it's a German film, so it's ended up as more of a cult film.

I'd also like to give honourable mentions to Labyrinth, Star Wars Episode IV, Pokemon 2000 (obvs) and Disney's Mulan.