Off the top of my head, the original screenplay idea for
I, Robot that Harlan Ellison wrote many moon ago. I have the illustrated copy of it that they made, and it sounds (and looks intriguing).
I have no idea how good/bad the movie they actually made is, but the fact that, from what I've heard, it's not actually based on any of Asimov's excellent stories is disappointing. So much good stuff they could have used (like Donovan and Powell
).
Peace & Luv, Liz