Infernal Affairs 無間道 (2002)

This is probably my favorite scene in this film. Undercover cop Chan Wing Yan (Tony Leung Chiu Wai) confronts his enemy, Inspector Lau Kin Ming (Andy Lau) in order to clear his name and reveal the real traitor in the Hong Kong Police Force.

This movie would be later be remade as the US film called The Departed (2006), set in Boston, with Leonardo DiCaprio and Matt Damon playing in Tony Leung's and Andy Lau's roles respectively.

Translation from Cantonese Chinese:

Lau Kin Ming: You sure know what you are doing? (Not a literal translation, he is literally calling him an experienced person)

Chan Wing Yan: I also went to the Police Academy.

Chan begins to arrest Lau.

Lau Kin Ming: You undercover cops are interesting, do all of you like to be on rooftops?

Chan Wing Yan: I'm not like you. I'm not afraid of light. You have the things I wanted?
(Chan is referring to his classfied police records, which Lau wants to destroy, so that Chan cannot clear his name.)

Lau Kin Ming: I do not think you brought the things I wanted.

Chan Wing Yan: So what does that mean? We came here to sunbathe?

Lau Kin Ming: Give me another chance.

Chan Wing Yan: Why should I give you another chance?

Lau Kin Ming: Before I did not have a choice. Now I want to choose to be a good man.

Chan Wing Yan: Good. Go tell it to the judge. See if he will let you be a good man.

Lau Kin Ming: You want me dead?

Chan Wing Yan: Sorry, I am a cop.

Lau Kin Ming: Who knows?

Chan then points his gun at Lau, to turn him in to the police. Then, Lau's partner (played by Gordon Lam Ka Tung) comes in to rescue Lau.

Lau's Partner, Inspector B: Freeze! Police! Drop your weapon and let Inspector Lau go first!

Chan Wing Yan: Your superior is Hon Sam's (a Triad criminal boss) mole! I have evidence! First, let's clear this up at the police station!

Inspector B: Drop your weapon! Drop your weapon!

Chan Wing Yan: I called the police already!

Inspector B: Why should I believe you?

Chan Wing Yan: You do not need to!

Chan then brings Lau forward while Lau's partner keeps his gun pointed. The Hong Kong Police begin to surround the building where the final conclusion of the film will take place.

I will not tell you the ending though, you have to watch the entire film. It's probably one of the best films to have come out of Hong Kong in the past decade.