Eat this, you outer-space octopus!

I didn't sign on for this shit. Monsters, sure, but civilians? Who ordered this operation anyway?

Come in, Cooper! Do you copy? Forget about Freeman, we're abandoning the base. If you have any last bomb targets, mark them on the tactical map. Otherwise, get the hell out of there! Repeat, we are pulling out and commencing airstrikes, give us targets or get below!

Eli Vance: "Why didn't they listen? We tried to warn them."
Scientist 2: "I never thought I'd see a resonance cascade, let alone create one."
Eli Vance: "Gordon, you're alive! Thank God for that hazard suit. I'm afraid to move him and all our phones are out. Please get to the surface as soon as you can and let someone know we're stranded down here. You'll need me to access the retinal scanners. I'm sure the rest of the science team will gladly help you."

I have no heart to give to Death. Perhaps, I'll give her the hearts of others. Yes, one-thousand should do it.

Mister, if you can get the power on, that train will take us straight to the surface. I would try it myself, but it's a long way down the generator room, and there are... things, in the way...

Scientist: "Do you think we should appeal to the alien authorities?"
Scientist 2: "Absolutely not!"

Please be advised that a noticeable taste of blood is not part of any test protocol but is an unintended side effect of the Aperture Science Material Emancipation Grid, which may, in semi-rare cases, emancipate dental fillings, crowns, tooth enamel, and teeth.

The Enrichment Center reminds you that the Weighted Companion Cube will never threaten to stab you and, in fact, cannot speak.

There's always a man. There's always a lighthouse There's always a city.

You can't break a man the way you break a dog or a horse. The harder you beat a man, the taller he stands.

But with this guy, it might have cost me some bad burns or an ass-rape. I'm all for risking my life, but I'm a little sensitive about asshole.

GLaDOS: "Look, you're wasting your time. And, believe me, you don't have a whole lot left to waste. What's your point, anyway? Survival? Well, then, the last thing you want to do is hurt me. I have your brain scanned and permanently backed-up in case something terrible happens to you, which it's just about to. Don't believe me? Here, I'll put you on:"
Strange voice: Hellooooooooo!
GLaDOS: "That's you! That's how dumb you sound! You've been wrong about every single thing you've ever done, including this thing. You're not smart. You're not a scientist. You're not a doctor. You're not even a full-time employee! Where did your life go so wrong?"

The Enrichment Center is required to remind you that the Weighted Companion Cube cannot talk. In the event that it does talk The Enrichment Centre asks you to ignore its advice.

Momentum, a function of mass and velocity, is conserved between portals. In layman's terms, speedy thing goes in, speedy thing comes out.