Here's a movie I liked! It's actually an international film (produced in Hong Kong, China). The title is "
Infernal Affairs". There are actually three movies in the series (1, 2, and 3). Worth watching if you don't mind reading subtitles while you watch! I guess you could get a dubbed version, but I think dubbed movies are cheesy. :P
Martin Scorsese is also planning to remake an American version of the movie with Brad Pitt rumoured as being the lead actor in the film.
Scorsese to remake Infernal Affairs
Infernal Affairs I Trailer
"...INFERNAL AFFAIRS is a tightly wound thriller which centers on two Hong Kong police officers - one a gang mole on the force and the other an undercover cop in the gang - who share the same objectives and who find their destinies intertwined in this high-octane police actioner."
Infernal Affairs I
Infernal Affairs II
Infernal Affairs III