Die Nibelungen from 1924 is probably the best movie of Fritz Lang in the terms of the skills and achievements taken over it, in fact it is way better than Metropolis that is my favorite movie ever...and it can easily compete to the Akira Kurosawa´s peak period movies or the 50´s movies I have seen since my childhood. I already know the bad points in terms of what this movie was for the Nazi propaganda being the wife of Lang a promoter of Hitler and his ideas and Hitler an admirator of the movie, but to be honest the movie goes really far far away from just being a dedicated movie "To the people of Germany". It is a movie that is advanced to its own time and as some have said before probably is the most UFA movie done by the UFA Studios.
Have a great Day!!