What are your favorite GLaDOS quotes? Mine are:

"Two plus two is f…f…f… f…10. IN BASE FOUR! I'M FINE!"
and
"Killing you and giving you good advice aren't mutually exclusive."

My favorite was always "Weeeeeeeeeeeeeeeeeeeeee." I thought it was so perfect and awesome the first time I heard it.

"There was even going to be a party for you. A big party that all your friends were invited to. I even 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 unlikable you are."

"Remember when the platform was sliding into the fire pit and I said 'Goodbye' and you were like 'No way' and then I was all 'We pretended we were going to murder you'? That was great."

"This next test is impossible"

My favorite:

"Unbelievable! You, [Subject Name Here] must be the pride of [Subject Hometown Here]!"

And of course not to orget:

"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!"

'Well done, android. Remember that android hell is a real place where you will be sent at thefrst sign of resistance.'

"As part of a previously mentioned required test protocol, we can no longer lie to you. When the testing is over, you will be... missed."

"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... '~Helloooooooooooooo~' 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?"

"In laymens terms: Speedy thing goes in, Speedy thing comes out!"

My very favorite is probably the second one Wess posted...  I also love the "when the testing is over, you will be... missed" quote because it's the first time we really see how crazy GLaDOS is.
My favorites that haven't been mentioned are:
"When the testing is over, you will be baked, and then there will be cake."
"That thing is probably some kind of raw sewage container. Go ahead and rub your face all over it!"
:P

" That made shoes for orphans "

"Wess" in an earlier post already started my favorite, but I'll finish it:

My best friend is adopted, and we played Portal together one night because I knew she would LOVE the sarcastic humor.  She thought the "It also says you were adopted, so that's funny too" was one of the best lines in the game.  :P

you will be fed and there will be cake

"Good news, I figured out what that thing you just incinerated is. It was a morality core they installed after I flooded the enrichment centre with a deadly neurotoxin to make me stop flooding the enrichment centre with a deadly neurotoxin, so get comfortable while I warm up the neurotoxin emitters."

We at the Enrichment Center would like to remind you that the Weighted Companion Cube will never threaten to stab you, and in fact, cannot speak.

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

"There will be cake." or "What are you doing with that thing that no one knows what it does"   

Something along the lines of that.  I haven't played the game in a while, but it's one of my favorites.

This game has great dialogue. Here's some more:

"The Enrichment Center promises to always provide safe testing environments. In dangerous testing environments, the Enrichment Center promises to always provide useful advice. For instance, the floor here will kill you. Try to avoid it."
"It was a fun test, and we're all impressed at how much you won. The test is over. Come back."
"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."
"You are kidding me! Did you just stuff that Aperture Science Thing We Don't Know What It Does into an Aperture Science Emergency Intelligence Incinerator? That has got to be the dumbest thing that- Whoa, Whoa, WHOAAA... Heh heh heh heh... Good news. I figured out what that thing you just incinerated did. It was a Morality Core they installed after I flooded the enrichment center with a deadly neurotoxin to make me stop flooding the enrichment center with a deadly neurotoxin. So get comfortable while I warm up the Neurotoxin Emitters."

"Don't believe me? Here, I'll put you on... '~Helloooooooooooooo~' That's you! That's how dumb you sound!"

I don't find Portals humour amusing at all.

"I don't find Portals humour amusing at all."

"Helloooo. Thats you! Thats how dumb you sound!"

""This next test is impossible"
"

Blasphemers! 

I loved the ending song ("Still Alive") though I don't know if it really qualifies as a line, per se.  My favorite actual line was already posted, but I'll post it again.

"There was even going to be a party for you. A big party that all your friends were invited to. I even 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 unlikable you are."

Where is everyone getting the quotes-verbatim, from?

"Where is everyone getting the quotes-verbatim, from?"

"BiggerBomb said:

"Where is everyone getting the quotes-verbatim, from?"

I think Wikipedia has a quote article for Portal."

"BiggerBomb said:

"Where is everyone getting the quotes-verbatim, from?"

I think Wikipedia has a quote article for Portal."

 "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... '~Helloooooooooooooo~' 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?"
That was my idea too, and don't forget GLaDOS said she was adopted.

" I don't find Portals humour amusing at all. "

" @Gizmo said:

" I don't find Portals humour amusing at all. "

Really?   wow,   I thoroughly enjoyed it,  If you like comedy may I ask what some of your favourite comedians are? just to see what your comedic tastes are like. "

I actually really like the line from Portal 2:
"We've both said things you're going to regret."

"your not smart, your not a scientist, your not a doctor, your not even a full time employee, where did your life go so wrong" 
 
"your entire life was a mathematical error, a mathematical error im about to correct" 
 
"you should marry that thing since you love it so much" do you want to marry that thing WELL I WONT LET YOU how does that feel"

mabey black mesa thats a joke haha fat chance

"Excellent. You remained resolute and resourceful in an atmosphere of extreme pessimism."