Although not a great film, Flash Gordon is certainly a fun one. Max Von Sydow is the plastic-haired Ming the Merciless, Richard O'Brien has a small role as a Pan-like treeman, and Queen wrote and performed one of the earliest feature film rock scores. Their music has helped the film maintain its cult classic status over the past 35 years, due in no small part to the fact that you just can't not sing along with the theme. He'll save every one of us! He's a miracle! King of the impossible! Of course Flash is just a man, but he can never fail, and neither can Queen.
And the end credit song/theme reprise: