An FBI undercover agent infiltrates the mob and finds himself identifying more with the mafia life, at the expense of his regular one.

FBI Technician: What's "Forget about it"?
Donnie Brasco: "Forget about it" is, like, if you agree with someone, you know, like "Raquel Welch is one great piece of ass. Forget about it!" But then, if you disagree, like "A Lincoln is better than a Cadillac? Forget about it!" You know? But then, it's also like if something's the greatest thing in the world, like, "Minghia! Those peppers! Forget about it!" But it's also like saying "Go to hell!" too. Like, you know, like "Hey Paulie, you got a one-inch pecker?" and Paulie says "Forget about it!" Sometimes it just means "Forget about it."
Lefty: [talking to Donnie] When I introduce you, I'm gonna say, "This is a friend of mine." That means you're a connected guy. Now if I said instead, this is a friend of ours that would mean you a made guy. A Capiche?
Lefty: There's the boss. And, under him, there's the skipper. You know how this works?
Donnie Brasco: Yeah, it's like in the army.
Lefty: Bullshit. The army is some guy you don't know telling you to go whack some other guy you don't know.
Donnie Brasco: You think I'm a rat...?
Lefty: How many times have I had you in my house? If you're a rat, then I'm the biggest mutt in the history of the Mafia.
Sonny Black: How can John Wayne die?
Lefty: Fuckin' Indians got him.
Lefty: A wise guy's always right; even when he's wrong, he's right.
Lefty: And listen to me, if Donnie calls... , tell him... if it was gonna be anyone, I'm glad it was him. All right?
Donnie Brasco: If I come out alive, this guy, Lefty, ends up dead. That's the same thing as me putting the bullet in his head myself.
Lefty: When they send for you, you go in alive, you come out dead, and it's your best friend that does it.
Joe Pistone: All my life I've tried to be the good guy, the guy in the white fucking hat. And for what? For nothing. I'm not becoming like them; I am them.
[Lefty is cooking dinner]
Lefty: Punch of salt.
Donnie Brasco: Punch?
Lefty: Punch. Punch of salt.
Donnie Brasco: Punch or pinch?
Lefty: Punch, punch. Not pinch. What'd I say? I say pinch?
Donnie Brasco: Nah, you said... you said punch.
Lefty: Sometimes you don't make no fuckin' sense, Donnie.
Maggie Pistone: God, why do you hate me when I love you so much?
Donnie Brasco: You think I hate you? I don't hate you. This job is eating me alive. I can't breathe anymore. And if I come out, this guy Lefty dies. They're gonna kill him because he vouched for me. Because he stood up for me. I live with that every day. That's the same thing if I put the bullet through his head myself, you understand? I spend all these years trying to be the good guy, you know? The man in the white fuckin' hat. For what? For nuthin'. I'm not becoming like them, Maggie, I am them.
Lefty: You're gonna walk out on me? You don't walk out on me. I walk out on you.
Jilly: Look, Left, I said I knew him. I didn't say I fucked him.
Japanese Waiter: Take your shoes off.
Joe Pistone: Take my shoes off? You take your pants off, what the fuck.
Lefty: Whackin' the boss... another thing I get left out of.
Donnie Brasco: Twenty years you know a guy, you fuckin' whack him out just like that over a lounge? That's beautiful.
[repeated line]
Lefty: I think I just shit my pants.
Lefty: Who the fuck am I? Who am I? I'm a, a spoke on a wheel. And so was he, and so are you.
[Lefty is banging a parking meter very loudly with a hammer]
Sonny Black: Hey, will you fuckin' stop that?
Lefty: How am I gonna get this thing open?
[looks back at the meter]
Lefty: Open Sesame!
Lefty: I got cancer of the prick.
Sonny Black: You know what we do when we find that rat, right, Lefty?
Lefty: 'Could be I found him already.
Lefty: How much money did you give that guy? A wiseguy never pays for his drinks.
Lefty: I'm tellin' ya, Donnie... nothin' but nothin' but right.
Nicky: The good news is, my dick is now a popsicle!
Lefty Ruggiero: Anywhere you go, all around the world, all the best cooks are men.
Sonny Black: You guys think this funny, I'm a skipper now, I got to answer, fifty grand month, kick up to Rusty, every month, one day I'm going to die and I'm going to be here in the same bar with all the same fucking guys, talking about the same fucking scams, never amount to nothing, cause that's how I'll know I'll be sent to fucking hell
Donnie Brasco: [to his fellow wiseguys, after he punches a man who tries to expose him] Fuckin' asshole, he grabbed my cock!
Nicky: [playing Gin] Look at this hand. This ain't a hand. This is a fuckin deformed Creature from the Black fuckin Lagoon's claw I got here.
Lefty: If anything should happen to me... make sure Annette gets the car.
Donnie Brasco: Hey Richie, what are you trying to do, get me killed with that fucking suit?
Richard 'Richie' Gazzo: What?
Donnie Brasco: That fucking car, purple fucking car. Don't say the word plotz, you understand?
Richard 'Richie' Gazzo: Yeah, yeah.
Lefty: She's a good woman, Annette. One broad, that's enough for anyone.
Lefty Ruggiero: Thirty years I'm busting my hump. What have I got?
Lefty: In all the five boroughs, I'm known, forget about it, I'm known all over the fucking world, anybody asks about Lefty from Mulberry Street, you're pissing up the world fucking street my friend
Nicky: C'mon Donnie, let's fillet this fat fuck.
Lefty: Whose dat guy?
Nicky: That's Donnie, Don da'jeweler.
Donnie Brasco: [Joe's kids are giving him the silent treatment] I bet you can't get through breakfast without saying three words
Daughter: [beaming up at him] You lose!
Sonny Black: I like it. I like it big time!
Tim Curley: Standard procedure is that he has to check in with us every day, he might miss a day or two here and there, it was three weeks ago, we can't tell you because we don't know, there's war going on in the mafia family where Joe is undercover, three leaders of a rival faction have been murdered, he's right in the line of fire, not because he's one of us because he's one of them, who he's close to, they're all the top dogs now, it's not a problem we anticipated, we have got to pull him out
Lefty: I never hear from my boss until he dies, then my whole life gets turned upside down!
[last lines]
Maggie Pistone: Joe... It's over, honey. Come on, come home.
Lefty: A guy like you don't touch a made guy, you know what I did yesterday? I went in front of the skippers, I'm going on the record with you, nobody can touch you now, I'm your man, Jesus Christ couldn't touch you because I represent you, keep your nose clean, be a good earner follow the rules, and who knows? Maybe one day they open the books you get straightened out, become a wise guy, a made guy, I'd die with you Donnie