Marty McFly

— Hey, Doc! Where you goin' now? Back to the future?
— Nope. Already been there.

— Doc, look. All we need is a little plutonium.
— I'm sure that in 1985 plutonium is available in every corner drugstore, but in 1955, it's a little hard to come by.

— You better face up to it, son, because if you don't go out there...
— What? What if I don't go out there?
— You're a coward.
— And you'll be branded a coward for the rest of your days.
— Everybody everywhere will say: «Clint Eastwood — is the biggest yellow belly in the West».

— Quiet. I'm going to read your thoughts. Let's see now. You come here from a great distance?
— Yeah. Exactly.
— Don't tell me! You want me to subscribe to the «Saturday Evening Post».
— No.
— Not a word now! Quiet. Donations. You want me to make a donation to the «Coast Guard Youth Auxiliary».
— Doc... I'm from the future. I came here in a time machine that you invented. Now, I need your help to get back to the year 1985.
— My God! Do you know what this means? It means that this damn thing doesn't work at all!

— You're a slacker. You remind me of your father when he went here. He was a slacker, too.
— Can I go now, Mr. Strickland?
— Your band is on the roster for the dance auditions after school today. Why even bother? 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.
— Yeah, well, history is going to change.

— Doc! Doc, come in!
— Marty, come in.
— Listen, Biff's guys chased me into the gym and they're gonna jump... me.
— Then get out of there!
— No, Doc, not me. The other me. The one that's up on stage playing «Johnny B. Goode».
— Great Scott! Your other self will miss the lightning bolt. You won't get back to the future and we'll have a major paradox!
— Wait. A paradox? You mean one of those things that can destroy the universe?
— Precisely.

So, you're my uncle Joey. Better get used to these bars, kid.

— Jennifer could conceivably encounter... her future self. The consequences of that could be disastrous.
— Doc, what do you mean?
— I foresee two possibilities. One, coming face to face with herself 30 years older... would put her into shock, and she'd simply pass out, or two, the encounter could create a time paradox, the results of which could cause a chain reaction that would unravel the very fabric of the space-time continuum and destroy the entire universe. Granted, that's a worst-case scenario. The destruction might, in fact, be very localized, limited to merely our own galaxy.
— Well, that's a relief.

— Why do you let those boys push you around like that for?
— They're bigger than me.
— Stand tall. Have some respect for yourself. If you let people walk over you now, they'll walk over you the rest of your life. Look at me. You think I'll spend my life in this slop house?
— Watch it, Goldie.
— No, sir! I'll do something. I'll go to night school. One day, I'm going to be somebody.
— That's right. He's going to be mayor.
— Yeah, I'm... Mayor! Now that's a good idea! I could run for mayor.
— A colored mayor. That'll be the day.
— Wait and see. I will be mayor. I'll be the most powerful man in Hill Valley and I'm going to clean up this town.
— Good. You can start by sweeping the floor.

— That's right, Doc. November 12, 1955.
— Unbelievable that old Biff could have chosen that particular date. It could mean that that point in time inherently contains... some sort of cosmic significance, almost as if it were the temporal junction point... for the entire the space-time continuum. On the other hand, it could just be an amazing coincidence.

— I'm sorry, Doc. It's all my fault you're stuck back there. I never should have let Biff get to me!
— Well, there are plenty worse places to be than the Old West. I could've ended up in the Dark Ages. They probably would have burned me at the stake as a heretic or something.