There is a rumor that Roland Emmerich will direct an adaptation of Isaac Asimov's The Foundation Trilogy, but I'm not getting my hopes up. My lack of enthusiasm isn't due to the works of Asimov or Emmerich but rather my own experiences.
Back in 1981, there was buzz about Asimov's Foundation Trilogy being made into three movies to be released in three consecutive months. My mind churned, and I wondered who would be cast as Hari Seldon, Salvor Hardin, and The Mule. Alas, all of my conjecture was for naught because the movie was never made. However, it did start a game that I now play with friends and family: If you were casting a favorite book as a movie, who would you choose?
One book series that my wife and I cast several times over the years is Anne McCaffrey's The Dragonriders of Pern. This series is one of the more interesting ones to play with due to the telepathic communications between the riders and their dragons, which allows for the addition of voice actors. Consider James Earl Jones as Mnementh, F'lar's bronze dragon, Glenn Close as Ramoth, Lessa's gold dragon, and Laurence Fishburne as Canth, F'nor's brown dragon. Thinking about it, I'd probably be over budget on just the voices of the dragons.
A favorite from the horror genre is George R.R. Martin's Fevre Dream. In this different kind of vampire story, the vampires are a separate species evolved to prey upon humans. Rather that taking place in some European castle or the Pacific Northwest, Fevre Dream is set along the Mississippi River in the mid-19th century. Think of Twain's Life on the Mississippi meets Dracula, and you get the idea. Robbie Coltrane would make a formidable Captain Abner Marsh, a riverboat captain and owner of the Fevre River Packet Company; Orlando Bloom would play Joshua York, the vampire hero; and Pierce Brosnan would be Damon Julian, the vampire villain.
Let me know whether you agree with my casting picks for these books. Also, play along in the discussion, and share your casting selections for a favorite book that is not a movie. Just remember that miscasting could cause people to question your judgment (like how Billy Crystal questioned Edward G. Robinson being in The Ten Commandments) or, hypothetically, cause the picture to crash and burn at the box office and be compared to The Clan of the Cave Bear for all time.