Well personally surveying my family (parents are 79) their friends that i know, my family and friends my age, and my kids (19-22) and the kids they know.....
Definitely a Disney movie - and I'm a huge Star Wars nerd and my entire family is too.....
But we run into more people (especially younger) that have not seen SW then people who have not seen Lion King for example. In fact I don't know anyone that has not seen Lion King and/or Toy Story. Even my parents saw those and their friends too (via the grandkids, etc.).
Wizard of Oz would be up there but I know young people now that have not seen it - no interest in something so old.
And I know teens, etc. that never saw the original Jurassic Park for example.
It's just that every kid went through the phase of watching every Disney movie pretty much. and their parents had seen them before anyway... and the grandparents via the grandkids at least.