Dune proved that fans are as excited about sci-fi adaptations as ever before, but several iconic books still haven't reached the silver screen.

Film sci-fi is often original, with stories that were made specifically for the screen, but there have also been many, many sci-fi adaptations. Many classic novels have been made into sci-fi movies, even previously thought unfilmable ones like Dune, but there are still many great sci-fi novels out there that have never made the...