At the risk of courting downvotes, Brazil from 1985. Not 100% sci-fi, as there are some comedy/fantasy/horror elements, but boy is it just wild. I don't know where Terry Gilliam gets his inspiration from.
Brazil suggest the terrorist bombings are really just explosions caused by bad plumbing.
Robocop and Running Man portray similar scifi futures / society.
Is there some dislike for Terry Gilliam? Can't think why anyone would want to downvote Brazil here.
I would actually consider it to be a free adaption of Orwell's 1984.
Every time.