Infernal Affairs (無間道 / 无间道 / インファナル・アフェア) is a crime thriller released in 2002, which revolves around two undercover moles - a triad member who infiltrates the police force and the other who is an undercover cop in a major triad gang. The two eventually seek each other out. - Infernal Affairs (2002) - The Departed (2006)

What did you think of either film, and what parts did you find the most memorable?

If you have seen both, what do you think of the changes made to the original in the latter movie?