Many people recommend Idiocracy as a view to the future.
Trouble is, the movie is just a comedic romp more than anything else. Apart from the very politically incorrect 5 minutes, its misleading and wrong.
If the co-Alpha theories are correct (Im not saying they are) - the future would be much more than just dirty and dull. It would be violent and brutal.
To that end, I have other movies that are better fits to this vision:
Ciudad Del Dios (City of God) - about gangs in a Brazillian Favela.
Elite Squad (Tropa De Elite) - also about favelas, but from a police point of view.
Bus 174 (Onibus 174) - a true footage hijacking also in Brazil.