John Steakley's classic Armor would rule as a movie, although the way it's separated into two parts it wouldn't make a very good video game.
Tad Williams' Otherland series, but only with one movie per book and only by Peter Jackson. Would also make an excellent FPS/survival game (i.e. Stalker) or WOW-style MMORPG. The Memory, Sorrow, and Thorn trilogy would be good too.
Steven Brust's "Vlad Taltos" novels would make good movies or games as well, and Cowboy Feng's Space Bar and Grille would make an awesome movie.
And any of Lois McMaster Bujold's "Miles Vorkosigan" books, or Tanya Huff's "Honor" books, or Elizabeth Moon's excellent "Sheepherder" trilogy, or -
Dang, now I'm depressed. I can choose between Mamma Mia, The Mummy 3, Sisterhood of the Traveling Pants 2, Step Brothers, and Space Chimps. WTF? Seriously, Hollywood, WTF?