When you think Sci Fi and original rock music, I hope your mind goes to Queen. They had original music on both Flash Gordon and The Highlander Movie. These songs were not just filler, but have come to represent their franchises. Even people who hate the Flash Gordon movie love the theme. Highlander was so associated with the Heroes of the Universe that they used it as the theme for the show six years later. We won't go into how many fantasy and science fiction films have used Queen songs, but will mention the amazing Shaun of the Dead soundtrack has Queen songs.