Yosharian:

I must not fear.
Fear is the mind-killer.
Fear is the little death that brings total obliteration.
I will face my fear.
I will permit it to pass over me and through me.
And when it has gone past I will turn the inner eye to see its path.
Where the fear has gone there will be nothing... Only I will remain.

One of my favorite quotes of all time.

"What can change the nature of a man?"

It was not the question in itself, but the context behind it and irony of asking it again.
Just play the bloody game right now!

Blunderboy:

Rocknrolla

Johnny Quid: You see that pack of Virginia killing sticks on the end of the piano?

Pete: Yes.

Johnny Quid: All you need to know about life is retained in those four walls.
You will notice that one of your personalities is seduced by the illusions of grandeur - the gold packet of king size with a regal insignia, an attractive implication towards grandeur and wealth, the subtle suggestion that cigarettes are indeed your royal and loyal friends, and that, Pete, is a lie.

Your other personality is trying to draw your attention to the flip side of the discussion, written in boring bold black and white, it's a statement that these neat little soldiers of death and in fact trying to kill you and that, Pete, is the truth.

Oh, beauty is a beguiling call to death and I'm addicted to the sweet pitch of its siren.
That which starts sweet ends bitter, and that which starts bitter ends sweet.
That is why you and i love the drugs and that is also why I cannot give that painting back. now please, pass me a light (or lie).

Pete: Oh you are something special, Mr johnny quid.

Always loved that one. I also liked when Lenny said "There's no school like the Old School, and I'm the fucking Headmaster!"

OP:
"For every one of us, living in this world
means waiting for our end. Let whoever can
win glory before death. When a warrior is gone,
that will be his best and only bulwark...
Endure your troubles today. Bear up
and be the man I expect you to be"
-Beowulf; lines 1384-1389

Truly the words that all Dark Ages warriors lived by.

Eh, I got a lot of them, so here's just a few...

"I love it when a plan comes together."- John "Hannibal" Smith, The A-Team

"Why can't we all just get along, Sammeth?" "That's because most of us are ****ed-up, Maximus."-from Sam and Max season 3 episode 2: The Tomb of Sammanmak

"I am not a thing! My name is Leonard Church, and you will fear my laser face!"- Epsilon-Church, Red VS Blue: Recreation

"Roads? Where we're going, we don't need... roads." - Doc Brown, Back to the Future

"Didn't anyone ever tell you there's one thing you never put in a trap, if you're smart, if you value your continued existence, if you have any plans about seeing tomorrow, there's one thing you never ever put in a trap... Me!"- The 11th Doctor

"I think I'll try defying gravity, and you can't pull me down..."- Elphaba, Wicked

"When it goes off, I'll be fine. It only affects computers, remember? And I... am a motherfucking ghost."- Church, Red VS Blue: Reconstruction

"...and maybe there are forces in this universe we don't understand. But I still believe we make our own miracles."- Huey Freeman, The Boondocks

"One day, I shall come back. Until then, there shall be no regrets, no tears, no anxieties. Just go forward in all your beliefs, and prove to me that I am not mistaken in mine." -The First Doctor, Doctor Who

"So, until we meet again, stay gold...BANG..." T.O.M., Toonami

bean burrito:
I'll paraphrase, because I'm too lazy to track down the exact wording, but:
"Never forget what you are, for the world will not. Armor yourself in it, for then nobody can use it against you'
-Tyrion Lannister

I think you got the wording exactly right.

In video games, I'd say the whole war never changes speech. That thing was awesome, especially with the animation to go along with it in fallout 3.

TV: I'd have to say Bazinga has found a place in my heart. go Sheldon

Books: seeing that I'm actually reading game of thrones right now I'd say this one is pretty good

Winter will never come for the likes of us. Should we die in battle, they will surely sing of us, and it's always summer in the songs. In the songs all knights are gallant, all maids are beautiful, and the sun is always shining. - Brienne the Beauty

'Impossible' is just a word to let people feel good about themselves when they quit.
Vyse, Skies of Arcadia

Whenever a task seems insurmountable (or I'm just being lazy) this quote springs to mind.

Survival is overrated you need to live a little too- Celeste mirrors edge

"A God named Fred?" - Percy Jackson
"Europa's death was probably important to her." - Percy Jackson

"When someone is in your heart, they're never truly gone. They can come back to you, even at unlikely times." - Mitch Albom, For One More Day

"But she wasn't around, and that's the thing when your parents die, you feel like instead of going in to every fight with backup, you are going into every fight alone." - Mitch Albom, For One More Day

I don't remember the character name in For One More Day, but it was one of Mitch Albom's two books that were fictional. I've got TONS of quotes that stuck with me, whether fictional or real people. (Though some are just funny as hell. Like the Percy Jackson ones.)

i'm glad to have you as my friend...

-some guy i helped in skyrim right before i brutally murdered him.

Adam Jensen - Do I trust mankind to save itself? That's what Eliza was asking. The truth is.... I don't know. After everything I've seen, all the fighting and chaos around me, I only know what I want to believe: somehow, human decency will triumph.

"Life moves pretty fast. If you don't stop and look around once in a while, you could miss it."

- Ferris Bueller, Ferris Bueller's Day Off

"Half as long..."

"... Twice as bright."

- Cole and Zeke, Infamous 2

"I am vengeance. I am the night! I! AM! BATMAN!"

- Batman, Batman: The Animated Series

Zap 'em with your sirens man. Zap 'em with your sirens. -The Photojournalist

This is the way the fucking world ends. Look at this fucking shit we're in man. Not with a bang, but with a whimper. And with a whimper, I'm fucking splitting, Jack. -The Photojournalist

"All right, then, I'll go to hell"- Huck Finn

I will have such revenges on you both, That all the world shall--I will do such things,-- What they are, yet I know not: but they shall be. The terrors of the earth.- Lear

Work, the what's-its-name of the thingummy and the thing-um-a-bob of the what d'you-call-it.- Psmith

How often have I said to you that when you have eliminated the impossible, whatever remains, however improbable, must be the truth? -Sherlock Holmes

Jelly Baby?- The Doctor

"Never back up. Your opponent can see what's behind you. You can't."
-Cain (Heroes Die, Acts of Caine 1)

"We do naught but scratch the world, frail and fraught. Every vast drama of civilizations, of peoples with their certainties and gestures, means nothing, affects nothing. Life crawls on, ever on."
-Kallor (Deadhouse Gates, Malazan Book of the Fallen 2)

"For Men, no circle is ever closed. We walk ever in spirals."
-Drusas Achamian (The Warrior Prophet, Prince of Nothing 2)

"When a woman, whether she's a wife, a lover, or a slave you've purchased to be a wife or lover, leaves you repeatedly ... take the hint."
-Dominar Rygel XVI (Farscape, 4.1 Crichton Kicks)

"My friend, one thing you have to learn. There is always time for beer."
-D'Argo (Farscape, 2.15 Won't Get Fooled Again)

There are far too many quotes from far too many different sources and I unfortunately don't remember them all. One of my favorites that I do remember is "When the rich are too rich there are ways, and when the poor are too poor there are ways"- The Good Earth. I think this quote also is a good thing to keep in mind considering the current status of the economy. If I do remember more I'll be sure to post them.

And still one more.

This one I've carried with me as holy writ since I first read it.

People are stupid. They can be fooled into believing anything; either because they want it to be true, or because they are afraid it is true.

--Zeddicus Zul Zorander, Wizard's First Rule by Terry Goodkind

At first I remembered it because it was awesomely cynical (and that was cool and edgy when I was in high school), but then I actually started to think about it. It sort of crystalized when I read Hogfather

'All right,' said Susan. 'I'm not stupid. You're saying humans need... fantasies to make life bearable."

"REALLY? AS IF IT WAS SOME KIND OF PINK PILL? NO. HUMANS NEED FANTASY TO BE HUMAN. TO BE THE PLACE WHERE THE FALLING ANGEL MEETS THE RISING APE"

'Tooth fairies? Hogfathers? Little- "

"YES. AS PRACTICE. YOU HAVE TO START OUT LEARNING TO BELIEVE THE LITTLE LIES"

'So we can believe the big ones?"

"YES. JUSTICE. MERCY. DUTY. THAT SORT OF THING"

'They're not the same at all!"

"YOU THINK SO? THEN TAKE THE UNIVERSE AND GRIND IT DOWN TO THE FINEST POWDER AND SIEVE IT THROUGH THE FINEST SIEVE AND THEN SHOW ME ONE ATOM OF JUSTICE, ONE MOLECULE OF MERCY. AND YET-- "

Death waved a hand. "AND YET YOU ACT AS IF THERE IS SOME IDEAL ORDER IN THE WORLD, AS IF THERE IS SOME... SOME RIGHTNESS IN THE UNIVERSE BY WHICH IT MAY BE JUDGED"

'Yes, but people have got to believe that, or what's the point---"

"MY POINT EXACTLY"

--Susan having a conversation with her grandfather, Hogfather by Sir Terry Pratchett

"Power corrupts. Absolute power...is a whole lot of Fun!" -Gnarl, 'Overlord series'

"You're still upset about that time I made you explode, aren't you? I can tell." - Skulduggery meeting Vengeous, 'Skulduggery Pleasant: Playing With Fire'

'What man is a man who does not make the world better' Balian, Kingdom of Heaven

"Does the distance one travels from center make one more free
to move?

No. Freedom has two parts: potential and resolution; as
metaphor has two parts: form and interpretation. Of course,
the two are intertwined. Metaphor lines the road to freedom,
as symbols and words are the bricks and mortar of meaning.
Freedom is being the bricoleur, the mason." -Durandal

"Sometimes all defeat teaches you, is that you lost"

-Master Li of Two Rivers (Jade Empire)

It may sound defeatist but actually it reminds me that not every conflict is worth analyzing and not every battle is worth engaging, only those with an acceptable risk and a possibility of learning something regardless of outcome.

"I see in Fight Club the strongest and smartest men who ever lived. I see potential. I see...squandering. Goddammit, and entire generation pumping gas, waiting tables, slaves with white collars. Advertising has us chasing cars and clothes, working jobs we hate so we can buy shit we don't need. We're the middle children of history, man, no purpose or place. We have no great war, no great depression. Our great war is a spiritual war, our great depression is our live. We've all been raised on television to believe that one day we'd all be movie gods an rock stars and millionaires. But we won't. And we're slowly realizing that fact. And we are very, very pissed off."

-Tyler Durden, Fight Club

"Not Today"
-Syrio Forel's prayer to Death, Game of Thrones

Wyrd byd Swydost (Fate is inexorable)

Uthred of Bebbanburg (Bernard Cornwells Viking series)

Run and hide if you want to, you won't live a second longer

Blonde viking - 13th Warrior

We Do Not Sow

Words of House Greyjoy- Game of Thrones

All Viking related, the first two because they sum up my views on fate, that while actions may impact it, you can never truly escape it.

The third one just cause I think it's the best House Words by far, with the Starks a close second (but serious, 'Hear me Roar?' 'As High as Honour' Laaaammme)

SMAC is full of these every time you research a technology. Some of my favourites:

"Resources exists to be consumed. And consumed they will be, if not by this generation then by some future. By what right does this forgotten future seek to deny us our birthright? None I say! Let us take what is ours, chew and eat our fill."

-CEO Nwabudike Morgan.

"Man has killed man from the beginning of time, and each new frontier has brought new ways and new places to die. Why should the future be different?"

-Col. Corazon Santiago

"What Goes up ... better doggone well stay up!"

- Morgan Gravitonics, Company Slogan

"Some would ask how could a perfect God create a universe filled with so much that is evil. They have missed a greater conundrum: why would a perfect God create a universe at all?"

-Sister Miriam Godwinson

I need to stop before I type every quote in the game.

one does not want to acknowledge the mistakes of their youth
-Char Aznable UC0079

One that always makes me laugh, the head of EPA from the Simpsons movie:
Underling: "Sir, you've gone mad with power!"
Russ Cargill: "Of course I have! Have you ever tried going mad without power? Its boring, no one listens to you".

And words to live by:

Capt. Malcolm Reynolds: [RE: What they found on Miranda] This record here's about twelve years old. Parliament buried it and it stayed buried until River here dug it up. This is what they were afraid she knew. And they were right to fear. There's a universe of folk who're gonna know it, too. Someone *has to* speak for these people.
[pause]
Capt. Malcolm Reynolds: Y'all got on this boat for different reasons, but y'all come to the same place. So now I'm asking more of you than I have before. Maybe all. Sure as I know anything, I know this - they will try again. Maybe on another world, maybe on this very ground swept clean. A year from now, ten? They'll swing back to the belief that they can make people... better. And I do not hold to that. So no more runnin'. I aim to misbehave.

Always sends a shiver when I hear Mal say this.

"They are eating her... and then they're going to eat me... oh my gooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo..."

"What you speak of is treason" - Ned stark

"Only if we lose" - Petyr Baelish

Dont know if he said those exact words in the book, but they said them in the series and it was probably one of my favourite scenes from the first series of game of thrones from one of the very best schemers I have ever seen created in a work of fiction.

I've read through the first 2 pages and no one has said, "Nothing is true, everything is permitted."

Solf J Kimblee was always my favorite philosophical waxer.

Kimblee: In my view, you are the ones that I can't understand.
To seek for justice in a special place like a battlefield is what's strange.
Is it heretical to kill with alchemy?
Is it better to kill with a gun?
Or is it that you were prepared to kill one or two, but can't bear killing thousands?
When you wore this of your own will, weren't you already prepared?
If you don't like it, you shouldn't have worn it in the first place. You moved forward onto this path on your own, why are you playing the victim now?
If you're going to take pity on yourself, don't kill people in the first place.
Don't avert your eyes away from death.
Look forward.
Look at the people you're killing in the face.
And don't forget them.
Don't forget.
Don't forget.
They won't forget you either.

"Don't guess and assume or come to conclusions, or you'll be surrounded by stupid illusions."
-Tusken Elder, from the machinima "The Parable of Foot-in-Mouth"
A memorable line that doubles as damn good advice. It has stayed with me for 12 years.

dalek sec:
also from the Warhammer 40K world, namely from the ending of the Dawn of War 2 game I think.

And they say that games are waste of time. :]