1. Metropolis
What It Is: A 1927 German science fiction film. Considered to be the first science fiction epic, and one of the greatest movies of the silent era. The movie follows young Freder, son of the powerful leader Joh Frederson, who has lived a sheltered life, unaware of the horrible conditions the lower class endures. They work in giant dangerous machines underneath the city, providing power to the richer class above ground. Freder wanders out one day and sees all this, and moved with pity, takes the place of one of the workers. Later, he stumbles across a secret church where the workers go, to hear sermons from the beautiful Maria who promises a time when a messiah will come and lead them to freedom. Meanwhile, Freder's father Joh is concerned by the absence of his son, and turns to the mad scientist Rotwang find what's become of him. When they find out about Maria and her church, Rotwang kidnaps her and replaces her with a robot designed to mimic her appearance and behavior.
Why A Remake Wouldn't Work: Despite generally positive reviews on its release, the main appeal of it was it's cutting edge visuals, which many times wowed the audience into spontaneous applause. Even today it's primary cause for acclaim is the landscapes, the skylines of the city, and it's amazing assortment of special effects, some of which are still impressive by today's standards. But a remake? All the amazing landscapes would be done in CGI, leading to less of an impressive skyline, and looking more like Coruscant in the Star Wars prequels. Seriously, the cinema today is saturated with mediocre graphics. A remake of Metropolis would offer nothing new or interesting, let alone being game-changing like it was in 1927.
The Only Way It Could Work: Give the director's helm to someone with a proven eye for stunning visuals, such as Terry Gilliam or Ridley Scott. Make sure they could preserve the awe-inspiring nature of the movie's look, while not getting so wrapped up in it that they neglect the story and characters.