Dune and Lord of the Rings. Both have such detail to their worlds that is rarely done well in other works. On top of the world building, I enjoyed the internal struggles that both Paul and Frodo had to go through to become better people and achieve their goals
It's amazing how Dune is becoming more and more relevant. Not because of any dystopia thing, but because the fundamental issues it talks about (unstable power systems, ecology and power, the right to sovereignty) are becoming more and more mainstream. If they make another movie, I think it could potentially do quite well.
In case you don't already know they are actually working on a new version of a Dune movie to be released in two parts, first movie at the end of 2020 IIRC, directed by Denis Villeneuve
