Part of growing up is doing what's best for the people you care about, even if sometimes, that means hurting someone else.

Oh V, V... got no sense of reverence... Expect if you found the goddamn Holy Grail, you'd fill it with caramel and Pop-Turds.

Gordon Freeman - it is you, isn't it? The Science Team has been tracking your progress with the Black Mesa security system. Unfortunately, so has the military. That suit of yours is full of tracking devices. Still, it's better than going naked in this place. It's cold in there, and you'll have to hurry. It could sap your suit power in a matter of moments! If you're bent on reaching the Lambda Complex, then you'll want to keep to the older, industrial areas where the security system is full of holes. It's worked for me, so far.

Bullets don't distinguish between tough and weak.

V: What is the sound of one hand clapping?
Zen Master: That depends - is someone clapping with you?

I was programmed to be helpful and answer any questions I was asked. I guess nobody bothered to restrict who I answer questions for.
That was probably pretty dumb, huh?

This is your fault. I'm going to kill you. And all the cake is gone. You don't even care, do you?

Who are you, that do not know your history?

You can't shake no hands when ye fist be clenched.

I am Andrew Ryan, and I'm here to ask you a question. Is a man not entitled to the sweat of his brow? 'No!' says the man in Washington, 'It belongs to the poor.' 'No!' says the man in the Vatican, 'It belongs to God.' 'No!' says the man in Moscow, 'It belongs to everyone.' I rejected those answers; instead, I chose something different. I chose the impossible. I chose... Rapture, a city where the artist would not fear the censor, where the scientist would not be bound by petty morality, where the great would not be constrained by the small! And with the sweat of your brow, Rapture can become your city as well.

You will soon have your God, and you will make it with your own hands.

Where's everyone going? Bingo?

People are ignorant. They'll feel better as long as someone is punished.

Uh, well, Mom always said I was a slow learner... but I eat FAST!!

You were almost a Jill sandwich!