Back to the Future (1985)

If the objection is that movies are slow, start here. Marty McFly is in 1955 before anyone has time to check their phone, and from then on the script never wastes a scene. Small setups early on, a flyer here, a skateboard there, all pay off later, which gives a first-time viewer the satisfying feeling of a story clicking into place. It's family-friendly without being childish, and the Library of Congress added it to the National Film Registry in 2007. Ignore the sequels for now: this one stands completely on its own.