Planet of the Apes (1968)
Escape from New York (1981)
Mad Max 2 (The Road Warrior) (1981)
The War Game (1965)
Waterworld (1995)
Reign of Fire (2002)
Children of Men (2006)
Immortal (2004)
Daleks – Invasion Earth: 2150 A.D (1966)
Logan's Run (1976)
Blade Runner would have been top, however i'm not really convinced it's a dystopian future. Just the future. The same goes for
Gattaca, another which might have made my top 10.