If the OP's stipulation is it has to first
be a movie, like Star Wars then there may not be another. I say that cause Potter was dismissed as was LOTR it seems.
I'd say both however don't equal SW in terms of cultural impact. Both are part of the mainstream conscience though along with many others such as Bond, Batman or even Godzilla.
I mean culturally SW has original novels, rereleases, a running cartoon, toys for sale all the time even a yearly Convention. Potter, LOTR and Bond don't have all that. I'm guessing Batman doesn't count most likely?
I wouldn't even apply Avatar
frankly. I see a universe with potential but where are the original novels, toys a cartoon at least. Original novels at least would be "easy" but I don't hear of those. I'm not convinced there is a ground swell of interest for more Avatar in the vein of the excitement the first one had. A second will do well, don't get me wrong, but the story was a bland rehash of a Hollywood staple told better in other places.