(In no particular order that I will admit)
01) "Spectacular. You appear to understand how a portal affects forward momentum, or to be more precise, how it does not. Momentum, a function of mass and velocity, is conserved between portals. In layman's terms, speedy thing goes in, speedy thing comes out."
02) "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."
03) "Please note that we have added a consequence for failure. Any contact with the chamber floor will result in an 'unsatisfactory' mark on your official testing record, followed by death. Good luck!"
04) "The Enrichment Center is committed to the well being of all participants. Cake and grief counseling will be available at the conclusion of the test. Thank you for helping us help you help us all."
05) "Remember, the Aperture Science 'Bring Your Daughter to Work Day' is the perfect time to have her tested."
06) "If the Weighted Companion Cube could speak, and the Enrichment Center takes this opportunity to remind you that it cannot, it would tell you to kill it, because it would rather die than be a burden to you."
07) "Deploying surprise in five... four... Time out for a second. That wasn't supposed to happen. Do you see that thing that fell out of me? What is that? It's not the surprise... I've never seen it before. Never mind, it's a mystery I'll solve later, by myself, because you'll be dead."
08) "That thing you burned up isn't important to me. It's the fluid catalytic cracking unit. It made shoes for orphans. Nice job breaking it, hero."
09) "I'd just like to point out that you were given every opportunity to succeed. There was even going to be a party for you. A big party that all your friends were invited to. I invited your best friend the Companion Cube. Of course, he couldn't come because you murdered him. All your other friends couldn't come either because you don't have any other friends. Because of how unlikeable you are. It says so here in your personnel file: Unlikeable. Liked by no one. A bitter, unlikeable loner whose passing shall not be mourned. 'Shall not be mourned.' That's exactly what it says. Very formal. Very official. It also says you were adopted. So that's funny, too."
10) "Speaking of curiosity, you're curious about what happens after you die, right? Guess what? I know! You're going to find out first-hand before I can finish telling you, though, so I won't bother. I'll give you a hint: you're going to want to pack as much living as you possibly can into the next couple of minutes."
11) "We both said a lot of things that you're going to regret. But I think we can put our differences behind us. For science. You monster."
12) "We're a lot alike, you and I. You tested me. I tested you. You killed me, I... oh no, wait. I guess I haven't killed you yet. Well... food for thought."
13) "Congratulations. The test is now over. All Aperture technologies remain safely operational up to 4000 degrees Kelvin. Rest assured that there is absolutely no chance of a dangerous equipment malfunction prior to your victory candescence. Thank you for participating in this Aperture Science computer-aided enrichment activity. Goodbye."
14) "Have I lied to you? [pause] I mean, in this room?"
15) "Didn't we have some fun though? Remember when the platform was sliding into the fire pit and I said 'Goodbye,' and you were like 'No way,' Then I was all like 'We pretended we were going to murder you?'[sigh] That was great."
Here are a few of my favourite turret quotes as a bonus:
"Could you come over... here?"
"Is anyone there?"
"I don't blame you..."
"I don't hate you..."
"No hard feelings."
"Please put me down..."
"Hey! It's me!"
"I see you."
"There you are."
"Are you still there?"
The game really is quite funny. It almost makes me want to buy an x-box. Maybe they have it for PC? I can run some virtual Windoze to play it. I know, I will Google it. Google will tell me.