"I wanna root for THX 1138"
I just *grinned* so big that something fell off. While possibly not being so influential for latter works, it was somewhat 'prophetic' (IMO) and a nice dystopia. On that note, I recommend Terry Gilliam's Brazil or, for lighter viewing, the forever-considered-a-B-rate futuristic Cherry 2000.
http://www.imdb.com/title/tt0092746/

That one fits very well, considering some of the current news blurbs.