snarkerati published a great list of 50 Dystopian Movies. Their definition of a dystopia is:

A dystopia is a fictional society that is the antithesis or complete opposite of a utopia, an ideal world with a perfect social, political and technological infrastructure. Therefore a dystopia is an imaginary place or state in which the condition of life is extremely bad, as from deprivation, oppression, or terror.

I didn’t see all the films in the list, but I really like some of them:

• 50. Equilibrium (2002)
• 44. Strange Days (1995)
• 42. I Robot (2004)
• 30. Dark City (1998)
• 29. Total Recall (1990)
• 25. Gattaca (1997)
• 16. Pleasantville (1998)
• 9. Minority Report (2002)
• 7. The Matrix (1999)
• 5. Blade Runner (1982)
• 3. Brazil (1985)