So, I'd no sooner seen the newest and final HOBBIT film than the question came to me: are Peter Jackson's Tolkien adaptations the greatest fantasy films ever made? Certainly they'd have to be in contention. It cd be argued that, Tolkien being the greatest of all fantasy authors,* someone setting out to adapt his works has a built-in advantage, but I think that wd be to underestimate Jackson's own talents.
I remember when fantasy film meant WILLOW (fun but daft), LEGEND (pretty but boring), or LABYRINTH (muppets and rock stars? really?**) -- in fact, one of the things that got me interested in anime and manga was the realization that there was a lot of fantasy out there, far more than we were getting in US films, only in animated form. It didn't help that what American films were coming out were firmly in the 'B-movie' range, at best. We've come a long way now since then, with fantasy films now very much in the mainstream (the HARRY POTTER series, GAME OF THRONES, Peter Jackson).
Trouble is, I can't judge how great a movie the Peter Jackson LORD OF THE RINGS and HOBBIT are because I can't divorce them from their Tolkien content to arrive at a fair judgment. Similarly, when it comes to what's probably the most famous fantasy movie ever made, THE WIZARD OF OZ, its very familiarity makes it hard for me to judge on its own merits. What wd that film be like to someone who didn't grow up on it as a viewing tradition, year after year, in a society filled with references to it? And, of course, I haven't seen every fantasy film ever made, nor do I want to, so any judgment has to come from partial knowledge.
But, given those caveats, I'd have to say THE LORD OF THE RINGS and THE HOBBIT still wd have to rank at or near the top of the list.
So, the question: what's the greatest fantasy film ever made?
current reading: Brodie's LOCATION GUIDE to New Zealand sites filmed in THE HOBBIT movie(s). 
*I think his nearest rival to that claim wd be Lewis Carroll -- whom Tolkien didn't think wrote fantasy. But then Verne didn't think Wells wrote science fiction, so authors may not be the best judges of such things
**to be fair, I've never seen this one all the way through, so it may be much better than the bits and pieces I've seen wd indicate