U.S. television science fiction is a popular genre of television in the United States that has produced many of the best-known and most popular science fiction shows in the world. Most famous of all, and one of the most influential science-fiction series in history, is the iconic Star Trek and its various spin-off shows, which comprise the Star Trek franchise. Other hugely influential programs have included the 1960s anthology series The Twilight Zone, the internationally successful The X-Files, and a wide variety of television movies and continuing series for more than half a century.