"Gordon Freeman, in the flesh – or, rather, in the hazard suit. I took the liberty of relieving you of your weapons. Most of them were government property. As for the suit... I think you've earned it.
The borderworld, Xen, is in our control, for the time being... thanks to you. Quite a nasty piece of work you managed over there - I am impressed. That's why I'm here, Mr. Freeman. I have recommended your services to my... employers, and they have authorized me to offer you a job. They agree with me that you have 'limitless potential.
You've proved yourself a decisive man so I don't expect you'll have any trouble deciding what to do. If you're interested, just step into the portal and I will take that as a yes. Otherwise, well... I can offer you a battle you have no chance of winning. Rather an anticlimax after what you've just survived."
*a portal appears*
"Time to choose..."
— The G-Man, Endgame
"Well, it looks like we won't be working together."
*the player is teleported in front of an army of Alien Grunts*
"No regrets, Mr. Freeman..."
— The G-Man, "Refuse" Ending
"Wisely done, Mr. Freeman! I will see you up ahead."
— The G-Man, "Accept" Ending
Half Life: Opposing Force
"So Corporal Shephard, we meet at last. Please, don't think that I've been avoiding you, a great many matters require my attention in these... troubled times. I do hope you understand, and now I require a further indulgence on your part: I cannot close my report until every loose end has been tied up. The biggest embarrassment has been the Black Mesa facility, but I think that's finally taken care of itself."
*a nuclear weapon detonates in the background*
"Quite so. But there is still the lingering matter of witnesses. I admit I have a fascination with those who adapt and survive against all odds... they rather remind me of myself. If for no other reason, I have argued to preserve you for a time.
While I believe a civil servant like yourself understands the importance of... discretion, my employers are not quite so trusting and rather than continually subject you to the irresistible human temptation of telling all, we have decided to... convey you somewhere where you can do no possible harm... and where no harm can come to you. I'm sure you can imagine that there are worse alternatives..."
— The G-Man
Half Life 2
"Rise and shine, Mister Freeman - rise and... shine. Not that I wish... to imply that you have been sleeping on... the job. No one is more deserving of a rest, and all the effort in the world would have gone to waste until... well... let's just say your hour has... come again. The right man in the wrong place can make all the difference in the world. So wake up, Mister Freeman... wake up and smell the ashes."
— The G-Man
"This is the Freeman. The Combine's reckoning has come."
"Let this war end in either total victory or our extinction. No further compromise shall we allow. We take our stand beside you, here, upon this miserable rock."
"How could one man have slipped through your force's fingers time and time again? How is it possible? This is not some agent provocateur or highly trained assassin we are discussing. Gordon Freeman is a theoretical physicist who had hardly earned the distinction of his Ph.D. at the time of the Black Mesa Incident. I have good reason to believe that in the intervening years, he was in a state that precluded further development of covert skills. The man you have consistently failed to slow, let alone capture, is by all standards simply that - an ordinary man."
— Dr. Breen
"Well, Dr. Freeman, under other circumstances I like to think we might have been able to work together in an atmosphere of mutual trust and respect. Certainly, judging from your brief tenure at Black Mesa while I was its Administrator, you showed every promise of becoming a valuable and productive contributor to the scientific process. And yet... I'm not sure what spurred you to it... but there is really no place in this enterprise for a rogue physicist.
Your mentors are partly to blame, of course. My disappointment in Eli Vance and Isaac Kleiner is far greater than my sorrow over your unfortunate choice of career path. In a way, I suppose you could not have done otherwise. Who knows what seeds of iconoclasm they planted when you were young and gullible. But while they certainly share a great part of the responsibility for the recent troubles, it is you alone who have chosen to act with such willful disregard for humanity's future.
Tell me, Dr. Freeman, if you can. You have destroyed so much. What is it, exactly, that you have created? Can you name even one thing? I thought not."
— Dr. Breen
"Dr. Freeman, you really shouldn't be out there. At the moment of synapse as I teleport, this chamber will be bathed in deadly particles that have yet to be named by human science. Perhaps when I'll have the leisure to do the work myself, I'll name one of them after you. That way you won't be completely forgotten! When the singularity collapses, I'll be far away from here; in another universe, as a matter of fact. You, on the other hand, will be destroyed in every way it is possible to be destroyed and even in some which are essentially impossible!"
— Dr. Breen
Time, Dr. Freeman? Is it really that time again? It seems as if you only just arrived. You've done a great deal in a small time span. You've done so well, in fact, that I've received some interesting offers for your services. Ordinarily I wouldn't contemplate them, but these are extraordinary times. Rather than offer you the illusion of free choice, I will take the liberty of choosing for you if and when your time comes round again. I do apologize for what must seem to you an arbitrary imposition, Dr. Freeman. I trust it will all make sense to you in the course of… well, I'm really not at liberty to say. In the meantime, this is where I get off.
— The G-Man
Half Life 2: Episode One
*Adjusts tie angrily*
"We'll... see about... that."
— The G-Man
"So much for "better living through science."
— Unnamed Rebel
Half Life 2: Episode Two
"Doctor Freeemaaan. I realize this moment may not be the most convenient for a 'heart-to-heart', but I had to wait until your... 'friends' were otherwise occupied. Hm. There was a time they cared nothing for Miss Vance... When their only experience of humanity was a crowbar coming at them down a steel corridor. When I plucked her from Black Mesa, I acted in the face of objections that she was a mere child and of no practical use to anyone. I have learned to ignore such naysayers when... quelling them... was out of the question. Still, I am not one to squander my investments... and I remain confident she was worth far more than the initial... appraisal. That's why I must now extract from you some small repayment owed for your own survival. See her safely to White Forest, Doctor Freeman. I wish I could do more than keep an eye on you, but I have agreed to abide by certain... restrictions. Mmm.
[to Alyx] Well... now... listen carefully, my dear. When you see your father relay these words: Prepare for unforeseen consequences."
— The G-Man
"Is that the sound of a Geiger Counter or my lifespan counting down? It's both! That's right, here at Black Mesa, when we talk about half-life, we mean it in more ways than one. So make your peace and come to Black Mesa! (blasts headcrab zombie with shotgun) Here you'll win a chance to fight freaks of nature, escape countless safety hazards, wander aimlessly for hours, and die scared, tired, and alone."
— Gordon Freeman, Freeman's Mind