The Departed
In South Boston, the state police force is waging war on Irish-American organized crime. Young undercover cop Billy Costigan is assigned to infiltrate the mob syndicate run by gangland chief Frank Costello. While Billy quickly gains Costello's confidence, Colin Sullivan, a hardened young criminal who has infiltrated the state police as an informer for the syndicate, is rising to a position of power in the Special Investigation Unit. Each man becomes deeply consumed by his double life, gathering information about the plans and counter-plans of the operations he has penetrated. But when it becomes clear to both the mob and the police that there's a mole in their midst, Billy and Colin are suddenly in danger of being caught and exposed to the enemy-and each must race to uncover the identity of the other man in time to save himself.
Allstar Cast: Leonardo DiCaprio, Matt Damon, Jack Nicholson, Mark Wahlberg, Martin Sheen
Trailer:
http://www.youtube.com/watch?v=SGWvwjZ0eDc