Transformers

Optimus Prime: Before time began, there was the Cube. We know not where it comes from, only that it holds the power to create worlds and fill them with life. That is how our race was born. For a time, we lived in harmony, but like all great power, some wanted it for good, others for evil. And so began the war, a war that ravaged our planet until it was consumed by death, and the Cube was lost to the far reaches of space. We scattered across the galaxy, hoping to find it and rebuild our home, searching every star, every world. And just when all hope seemed lost, message of a new discovery drew us to an unknown planet called Earth. But we were already too late.

Witwicky motto: No sacrifice, no victory.

Bobby Bolivia: A driver don't pick the cars. Mmm-mm. Cars pick the driver. It's a mystical bond between man and machine.

MiKaela: You know what I don't understand? Why, if he's supposed to be, like, this super-advanced robot, does he transform back into this piece-of-crap Camaro?

Optimus: Our planet was once a powerful empire, peaceful and just, until we were betrayed by Megatron, leader of the Decepticons. All who defied them were destroyed. Our war finally consumed the planet, and the All Spark was lost to the stars. Megatron followed it to Earth, where Captain Witwicky found him. It was an accident that intertwined our fates. Megatron crash-landed before he could retrieve the Cube. He accidentally activated his navigation system. The coordinates to the Cube's location on Earth were imprinted on his glasses.
Ratchet: If the Decepticons find the All Spark, they will use it's power to transform Earth's machines and build a new army.
Optimus: And the human race will be extinguished. Sam Witwicky, you hold the key to Earth's survival.

Ironhide: Why are we fighting to save the humans? They're a primitive and violent race.
Optimus Prime: Were we so different? They're a young species. They have much to learn. But I've seen goodness in them. Freedom is the right of all sentient beings. You all know there's only one way to end this war: we must destroy the Cube. If all else fails, I will unite it with the spark in my chest.
Ratchet: That's suicide! The Cube is raw power, it could destroy you both!
Optimus Prime: A necessary sacrifice to bring peace to this planet. We cannot let the humans pay for our mistakes. It's been an honor serving with you all.

Captain Lennox: So why Earth?
Sam Witwicky: It's the All Spark.
Keller: All Spark? What is that?
Sam Witwicky: Well, they came here looking for some sort of cube-looking thing. Anyway, Mr. NBE-1 here, aka MEGATRON... That's what they call HIM... who's pretty much the harbinger of death, wants to use the cube to transform human technology to take over the universe. That's their plan.

Optimus: With the All Spark gone, we cannot return life to our planet. And fate has yielded its reward, a new world to call home. We live among its people now hiding in plain sight but watching over them, waiting, protecting them. I have witnessed their capacity for courage. And though we are worlds apart, like us, there's more to them than meets the eye. I am Optimus Prime, and I send this message to any surviving Autobots taking refuge among the stars. We are here. We are waiting.

Judy: That's how we know we live in a free land because there are no secrets. They would say, "Hey! Duck and cover!"