18. 'Star Trek'
The Starship Enterprise took off with a five-year mission: "To explore strange new worlds, to seek out new life and new civilizations," and it succeeded in creating the most beloved of sci-fi franchises, not just inspiring countless spinoffs but also codifying fan fiction as an art form. Gene Roddenberry's original series remains the foundation, with William Shatner's awesomely pulpy Capt. Kirk, Leonard Nimoy's logical Mr. Spock, Bones, Sulu, Uhura and Scotty. They make contact with bizarre and inexplicable life-forms – Romulans, Gorns, Joan Collins. During its three years, Star Trek suffered from low ratings until NBC pulled the plug, but thanks to the most doggedly loyal of TV cults (remember when "Trekkie" was an insult?), Roddenberry's vision lives long and prospers to this day.