These selected films -- which vary dramatically in quality, by the way -- have dominated the fantasy and science fiction genres in ways that few others have. Some (The Hobbit, The Lord of the Rings, Harry Potter, etc.) were preceded by books of the same name. Others (Star Trek, Star Wars, etc.) have spawned an "after the fact" publishing industry. I have not included franchises (however worthy) which seemed to target specifically the "YA" audience, but rather films with a broader appeal.
When I originally published a similar list a few years ago, I made the decision not to include films which had been announced, but not yet released. I have redacted that somewhat. I have included the 2021 release of Jurassic Park: Dominion as that film's release seems pretty much locked in stone. The release of other films, for example, Fantastic Beasts 3, 4, and 5; The Chronicles of Narnia: The Silver Chair; are still very up in the air. And the Star Trek reboot seems to have run its course.