Hopefully I remember this exchange correctly, two soldiers sitting outside the tent in Roche's encampment in Chapter II

"His mother comes in and says, "The elder and the recruiter are coming for you. He's slaughtering pigs at the time. So he takes a pig's eye and puts it between his buttocks."
"He did what?"
"He put a pig's eye in his arse. The elder and the recruiter enter and the mother says, 'Son, they've come to take you away to war.' He's standing with his back to them, his pants down. He spreads his cheeks and says, 'I can see that.'"
"Did they take him?"
"Not a chance."

I forgot to mention: "Triss, stop thinking with your vagina". This one always cracks me up :D

Nothing beats little children telling you, that 2 swords don't make you cool, but you seem to be a bit clumsy.

That and "Lesbomancy!"

The npc dialogue between Ch. 2 Troll and his missus (if you get them back together) is also pretty awesome. It's not what they say, it's how contrite he is.

I must've missed this comment... where and who?

"that was my doppleganger... i have 3 of them" geralt in prologe

"The only sight worse than a sad dwarf is a very sad dwarf"

Just something about the way Geralt says it.

Philippa says it while talking to Triss through the megascope. Watch out for the dialogue choices.

"I heard human women need only to sit astride a man's pants for their bellies to puff up"
conversation between two dwarves at the inn in vergen. its funny how the conversation just randomly comes up

"You're the noblest d'hoine"
"I am not a human"

Ioverth and Geralt
Geralt took my off guard by this line haha...yeah it is ture that Geralt was never a human in the game

Foltest: Where are we going?!
Soldiers: To battle!
Foltest: What do we want?!
Soldiers: Victory!
Foltest: This I like!
*Soldiers cheer*


Foltest: Fall back, gods dammit. I forbid you to die like imbeciles, hear me?!

I can't believe no one brought this up yet:
What about "OOOOOOODRIN!"? :P

3 most common line in combat:
"You Stink"
"How many more could there be"
"I m too old for this"

I can't exactly remember who it was but I had to laugh when one of the dwarfes in Vergen said Pen... instead of Stennis.