George McFly: Lorraine, my density has bought me to you.
Lorraine Baines: What?
George McFly: Oh, what I meant to say was...
Lorraine Baines: Wait a minute, don't I know you from somewhere?
George McFly: Yes! Yes! I'm George, George McFly! I'm your density. I mean... your destiny.

George McFly: Last night, Darth Vader came down from planet Vulcan and told me that if I didn't take Lorraine out that he'd melt my brain.

Marty McFly: Wait a minute, Doc. Ah... Are you telling me you built a time machine... out of a DeLorean?
Dr. Emmett Brown: The way I see it, if you're gonna build a time machine into a car, why not do it with some style?

[1955 Doc is watching a video of 1985 Doc]
Dr. Emmett Brown: What on Earth's this thing I'm wearing?
Marty McFly: Ah, this, this is a radiation suit.
Dr. Emmett Brown: Radiation suit? Of course, because of all the fallout from the atomic wars!

[In the past, Marty observes his dad's incompetence.]
Marty McFly: Jesus, George, it's a wonder I was ever born!

Mr. Strickland: You don't have a chance, you're too much like your old man. No McFly ever amounted to anything in the history of Hill Valley!
Marty McFly: Yeah, well, history is gonna change.

[Repeated line]
Marty McFly: If you put your mind to it, you can accomplish anything.

Dave McFly: [kissing George McFly on the head] See ya pop. Oooow, time to change that oil!

Dr. Emmett Brown: If my calculations are correct, when this baby hits eighty-eight miles per hour ... you're gonna see some serious shit.

[In 1955, Tab and Pepsi Free aren't invented yet]
Lou: You gonna order something, kid?
Marty McFly: Ah, yeah... Give me a Tab.
Lou: Tab? I can't give you a tab unless you order something!
Marty McFly: Alright, give me a Pepsi Free.
Lou: You want a Pepsi, PAL, you're gonna pay for it!

Goldie Wilson: I'll be the most powerful man in Hill Valley, and I'm gonna clean up this town.
Lou: [handing him a broom] Good, you can start by sweeping the floor.

[Lorraine's parents are talking about Marty McFly, Lorraine's future son]
Stella Baines: He's a very strange young man.
Sam Baines: He's an idiot. Comes from upbringing. His parents are probably idiots too. Lorraine, if you ever have a kid that acts that way I'll disown you.

[Dr. Emmet Brown is doubting Marty McFly's story about that he is from the future]
Dr. Emmett Brown: Then tell me, "future boy", who is president in the United States in 1985?
Marty McFly: Ronald Reagan.
Dr. Emmett Brown: Ronald Reagan? The actor?! Who's Vice President? Jerry Lewis?
Marty McFly: What?
Dr. Emmett Brown: I suppose Jane Wyman is the first lady! And Jack Benny is secretary of the treasury! I've had enough practical jokes for one evening! Good day, future boy!

[Marty McFly comes to his school in 1955]
Marty McFly: Wow, they really cleaned this place up. It looks brand new!

Marty McFly: Wait a minute, Doc, are you trying to tell me that my mother has got the hots for me?
Dr. Emmett Brown: Precisely.
Marty McFly: Whoa, this is heavy.
Dr. Emmett Brown: There's that word again; "heavy". Why are things so heavy in the future? Is there a problem with the earth's gravitational pull?

[The correct phrase is "So why don't you make like a tree and leave"]
Biff Tannen: So why don't you make like a tree and get outta here.

George McFly: Lou! Give me a milk...
[dramatic pause]
George McFly: Chocolate!

[Marty McFly arrives late for his take-off]
Dr. Emmett Brown: You got no concept of time!

Dr. Emmett Brown: Don't worry! As long as you hit that wire with the connecting hook at precisely eighty-eight miles per hour the instant the lightning strikes the tower ... everything will be fine!

[Last line]
Dr. Emmett Brown: Roads? Where we're going we don't need roads.

Dr. Emmett Brown: Next Saturday night, we're sending you back to the future!

Dr. Emmett Brown: I'm sure in 1985, plutonium is available at every corner drugstore, but in 1955 it's a little hard to come by!

George McFly: I know what you're gonna say, son. And you're right, you're right. But Biff just happens to be my supervisor, and I'm afraid I'm just no good at... confrontations.
Marty McFly: The car, Dad! I mean he wrecked it! He totaled it! I needed that car tomorrow night, Dad. Do you have any idea how important this is to me? Do you have any clue?
George McFly: I know, son. And all I can say is... I'm sorry.

Biff Tannen: I have your car towed all the way to your house and all you've got for me is LIGHT beer?

Marvin Berry: [on the phone, as Marty plays "Johnny B. Goode"] Chuck! Chuck! It's Marvin -- your cousin, Marvin BERRY. You know that new sound you're looking for? Well, listen to this!
[holds the receiver out]

Marty McFly: [watching a Honeymooners episode in 1955] Hey, I've seen this one. I've seen this one. This is a classic.
Milton Baines: What do you mean, you've seen this? It's brand new.
Marty McFly: I saw it on a...
[realizing]
Marty McFly: rerun.
Milton Baines: What's a rerun?

[Stella Baines is Marty's future grandmother.]
Stella Baines: Why do you look so familiar to me? Do I know your mother?
Marty McFly: Yeah, I think maybe you do.

[Marty learns the consequences of tampering with the past.]
Marty McFly: Sounds pretty heavy.
Dr. Emmett Brown: Weight has nothing to do with it.

[on the phone while all the clocks chime at once]
Dr. Emmett Brown: Is that my clocks I hear?
Marty McFly: Yeah Doc, it's 8 o'clock.
Dr. Emmett Brown: Great!! My experiment worked they're all exactly 25 minutes slow.
Marty McFly: Doc? Are you saying it's 8:25?
Dr. Emmett Brown: Precisely.
Marty McFly: Damn! I'm late for school!

Marty McFly: Do you know where Riverside Drive is?
Sam Baines: It's on the other end of town, a block past Maple. East end of town.
Marty McFly: A block past Maple? That's John F. Kennedy Drive.
Sam Baines: Who the hell is John F. Kennedy?

[on the phone]
Dr. Emmett Brown: Marty you might not want to hook up to the amplifier. There's a slight possibility of overload.
Marty McFly: Yeah I'll keep that in mind.

Marty McFly: [introducing his band] We're... uh... we're the Pitheads.

Lorraine Baines: Kids, we're gonna have to eat this cake by ourselves. Your Uncle Joey didn't make parole again.
Marty McFly: Uncle "Jailbird" Joey?

Marty McFly: [to Uncle Joey as a baby, playing in his playpen] So you're my Uncle Joey. Better get used to these bars, kid.

George McFly: Do you really think I should swear?
Marty McFly: Yes! Yes, god-damnit George, swear.

Dr. Emmett Brown: Oh my God they've found me, I don't know how but they found me.
Marty McFly: Who?
Dr. Emmett Brown: Who do you think, the Libyans! Run for it Marty!
Marty McFly: Oh shit!

[The DeLorean has just made the first time-jump.]
Marty McFly: Jesus Christ, Doc, you just disintegrated Einstein!
Dr. Emmett Brown: Relax, Marty, I didn't disintegrate anything! The molecular structure of both Einstein and the car remain completely intact!
Marty McFly: Then where the hell are they?!
Dr. Emmett Brown: The appropriate question is WHEN the hell are they!

[Talking about the Time Machine]
Marty McFly: So does it run on regular unleaded gasoline?
Dr. Emmett Brown: Unfortunately no, it needs something with a little more kick - plutonium.
Marty McFly: Plutonium... wait, are you telling me that this sucker is nuclear?!
Dr. Emmett Brown: No no no, this sucker's electrical, but it requires a nuclear reaction to generate the 1.21 gigawatts of electricity I need.
Marty McFly: Doc, you don't just walk into a store and buy plutonium... did you rip that off??
Dr. Emmett Brown: Shhhhhh!! Of course. From a group of Libyan nationalists. They wanted me to build them a bomb, so I took their plutonium and in turn, gave them a shiny bomb-casing filled with used pinball machine parts!

Dr. Emmett Brown: [Running out of the room] 1.21 gigawatts?! 1.21 gigawatts?!
Marty McFly: [Following] What the hell is a gigawatt?!

Marty McFly: Wait, you don't understand. If you don't play there's no music. If there's no music they don't dance. If they don't dance they don't kiss and fall in love and I'm history!

[Addressing the shocked expressions at the dance after playing a wild guitar solo]
Marty McFly: I guess you guys aren't ready for that, but your kids are gonna love it.

[Marty and Doc observe George's incompetence in 1955]
Dr. Emmett Brown: Where's your father?
Marty McFly: There.
Dr. Emmett Brown: Maybe you were adopted.

Dr. Emmett Brown: I remember when this was all farm land as far the eye could see. Old man Peabody owned all of this. He had this crazy idea about breeding pine trees.

Dr. Emmett Brown: The only thing powerful enough to generate 1.21 gigowatts of electricity is a bolt of lightning!
Marty McFly: [startled] What?
Dr. Emmett Brown: A bolt of lighting! Unfortunately, you never know when or where it's ever gonna strike!
Marty McFly: We do now.

Marty McFly: Doc, you disintegrated Einstein!

Marty McFly: That's Strickland? Jesus! Didn't that guy ever have hair?

Marty McFly: Why do you keep calling me Calvin?
Lorraine Baines: Calvin Klein? It's all over your underwear.

[Thinking that Marty is an alien]
Sherman Peabody: It's already mutated into human form! Shoot it!