Mark my words: When these hands are crushing your throat, your dying breath won't be an appeal to God or a message of love to your family. It'll be, "Thank you, Killbane."

Peace. Enjoy it while it lasts.

Cave Johnson: Greetings, friend. I'm Cave Johnson, CEO of Aperture Science. You might know us as a vital participant in the 1968 senate hearings on missing astronauts. And you've most likely used one of the many products we invented - but that other people have somehow managed to steal from us. Black Mesa can eat my bankrupt-...

Caroline: Sir, the testing?

Cave Johnson: Right. Now, you might be asking yourself, "Cave, just how difficult are these tests? What was in that phonebook of a contract I signed? Am I in danger?" Let me answer those questions with a question. Who wants to make sixty dollars? Cash. You can also feel free to relax for up to twenty minutes in the waiting room, which is a damn sight more comfortable than the park benches most of you were sleeping on when we found you. So! Welcome to Aperture. You're here because we want the best, and you're it. Nope. Couldn't keep a straight face.

Hey, hey, you gotta listen to me, you gotta hear me, are you listening? It's not real man! It's a lie, it's all lies. The government lies to us. They put robots in the drinking water, they put spies in the toilets - to watch us! You think it's a joke, the joke's on you, they're killing you! You are being harvested by a marketing machine! You're not free, you're slaves! Freedom is a lie! They use drugs to control you, they did it to me for a long time. You need love! I need you, you need me, I love you! Love me back!

Lester: It's hard to get motivated on a job without financial incentive.
Michael: You can't put a price on freedom.