We should be talking about the books, not the movies.
Anyways, I am a huge fan of both.
However, Tolkein made over 20 languages, including Elvish, Khuzdul (Dwarvish), Entish, and other languages with their own grammar and vocabulary. This is all for the well, carefully constructed universe of Lord of the Rings.
And he made more books beyond LotR, like the Silmarillion, that expand upon the LotR.
That shows incredible quality and dedication. This was not just a series, a story. This was a universe that was carefully crafted.
Although Harry Potter is one of my most beloved book and movie sereis’. Lord of the Rings takes the cake. Tolkein is beyond intelligent, and is one of the greatest men to set foot on this Earth. The depth of those books goes beyond what I am able to comprehend.