The king of science fiction authors whose works have been adapted into other media is Philip K. Dick, and I think it’s a shame he isn’t better known to the public. Dick’s stories tend to be extremely paranoid and often deal with questions about the nature of reality and consciousness. Here is a list (not complete) of movie/TV adaptations. Some of these definitely qualify as classics:
The Man in the High Castle
Total Recall
The Adjustment Bureau
Screamers
Next
A Scanner Darkly
Paycheck
Minority Report
Impostor
Blade Runner
The adaptations don’t always convey the tension and paranoia and dark humor in Dick’s stories.
For instance: neither Total Recall adapation is anything like the short story (We Can Remember It For You Wholesale), except for the basic concept. A miserable wage slave with a boring life craves excitement, so he goes to the Rekal company and has exciting memories of a spy mission to Mars installed in his brain. In the process of doing that, they discover that he really is a spy and his true memories have now become unlocked. The two movies take this as literal truth and merry hijinks and triple-breasted women occur.
Instead of using this as a springboard for a straightforward action story, Dick has fun with the concept. What would happen if other people had been messing around in your brain, planting or erasing memories for their own purposes?
Just a note about the Blade Runner movie:
Some things don’t make sense in the movie because they’re lifted from Dick’s story (DO ANDROIDS DREAM OF ELECTRIC SHEEP?) but they’re not used in context. In the story, humans have intense guilt about animals (most of which are near extinction) and feel obligated to keep one as a pet. Tyrell’s owl and Zora’s snake are remnants of this. Note that the test to identify a replicant involves questions that often reference animals — a calfskin wallet, a nude on a bearskin rug, a butterfly collection, a tortise in the desert. In the story this makes sense. In the movie, we don’t know why these questions would provoke an emotional response.
A clever detail in the story is that real animals are expensive and are subject to getting sick, etc., but since pets are a status symbol, many people have replicant pets that they pretend are real to their friends.
Also in the story, most educated/sane/healhy/ambitious/competent people have left earth, so those who stayed behind (the people we see in the story) are mostly misfits in some way. In the movie, all we have of this are the floating advertisements for jobs off-world.
Because so many people have left earth, there are a lot of empty buildings and a lot of the infrastructure is crumbling, like the run-down, empty building where J. F. Sebastian lives.
I love the atmosphere of the movie, especially the street scenes.