wiggydiggy
Guru
The one which is leading the poll was an adaptation of a short story (The Sentinel by Arthur C Clarke - I read that long before seeing the film) - and then spawned a full novel and sequel, also written by Clarke.
Dune, of course, was based on the novel by Frank Herbert (Again, I read it long before the first film was made). Not on the poll, but mentioned several times in the thread. I haven't actually seen the film, so not sure just how accurate an adaptation it is.
Starship Troopers was based on the Heinlen novel, and is actually a fairly accurate adaptation.
Another good one (IMO) not in the poll is I Robot, based on a story from the Asimov I Robot collection.
And The Bicentennial Man, also based on a novel by Asimov and Silverberg, which was itself based on a short story by Asimov.
There have been a few, some of which have been pretty good.
Starship Troopers - for the shower scene Paul Verhoeven agreed to also be nude, along with his cinematographer Jost Vacano, to put the cast at ease. It's probably one of the best nude scene I've seen as all the characters are talking as if they are in the mess rather than the showers.
I, Robot - Love that film, it gets criticised (rightly ) for too much product placement but that doesn't make it bad. I'd have loved a follow on TV series set in that world but it hasn't happened.