AMBER: albeit you could say it was a movie based on the books and not the diceless RPG. Lots of potential.
RIFTs: a relentless amount of imagery, characters, plots that could be tapped. I loved the early Dead Boy armor, as well as the phase world ship art!
PARANOIA: sounds like a sweet game to play for fun, I am sure a nail biting comedy/action/thriller could be made from it.
EXULTED: High fantasy combined with anime style combat. Sort of akin to Ninja Scroll.
Call of Chthulu: would be awesome! If done good enough so that your hairs stood on the back of your neck!
