A MGM classic from 1956. MGM was always paving new ground in the Sci-Fi genre. In this movie, they did away with rocket ships, and went in a totally new, if not radical direction. Earth has flying saucers and can travel much faster than light! It was powered by nuclear energy.
And the best part, is it predates NASA so no need for technical consultants!
This movie is when they built "Robbie The Robot". After he was built, at a cost of 7% of the films budget, Robbie made appearances in many other movies as well as TV shows, plus made special appearances at conventions. He sold at auction for over 5 million dollars last month.
The cast is also noteworthy. Leslie Nielsen, Richard Anderson, Earl Holliman, Warren Stevens, and others.