For me the first thing that comes to mind is Tales from Earthsea. I don’t think it’s excellent or anything and has plenty of problems but people act like it killed their dog. While it has its problems that have been covered extensively, I think it has a beautiful atmosphere and art.
IMO it would have been better received if it wasn’t advertised as an Earthsea adaptation and was just its own thing.
Robin hood was a massive movie in my childhood. The kid across the road had the whole set of toys, didn’t even know they were just.unsold star wars figures