The 2013 cycle
Start with Justice League: The Flashpoint Paradox, then Justice League: War, Son of Batman, Justice League: Throne of Atlantis, Justice League vs. Teen Titans, Justice League Dark, The Death of Superman, Reign of the Supermen and Wonder Woman: Bloodlines.
The later cycle
Green Lantern: Beware My Power, Legion of Super-Heroes and Justice League: Warworld lead into the three parts of Justice League: Crisis on Infinite Earths Part One and its sequels.
Standalone films
Most other DC films stand alone and can be watched in any order.
