"What are you gonna do? Bleed on me?" - Caleb from Blood 2 (I know he quotes something else, but that's from I've remembered this quote)

Isn't that from Monty Python and the Holy Grail?

Yep, but Caleb quotes that in both Blood games, too :P

My favorite Caleb quote is actually from Blood 2:

"When you get to Hell, tell them I sent you. You'll get a group discount."

"Hey! Stop making me fall!"
- Prince Alexander, King's Quest VI: Heir Today, Gone Tomorrow

Peace time is hard times, for mercers, like me.

"TV!"

from psychonauts. by far my fav quote and one of the reasons i will never forget playing that game.

also from psychonauts:

Kochamara: I've got the brain of a little girl back in my lab that could power a whole army of Psycho-Blaster death tanks... [realizes Raz is laughing at him] What's so funny?
Razputin: You've got the brain of a little girl?
Kochamara: ...I said, "in my LAB!"
Razputin: I think you've got the muscles of a little girl, too! Hahahaha
Kochamara: Good one

can be seen at 6:08 http://www.youtube.com/watch?v=QuCsgAkRpdk

while I don't like Hk-47 in kotor 2 (love him in kotor 1) this is my fav quote by him:
"Recitation: Once upon a time, organic meatbags bred out of control and filled the galaxy. There are different meatbags across different planets, all bumping into each other. They talk a great deal and threaten each other for various reasons, mostly involving mating, survival, and resources. It is really quite tiresome"

A few from Ryudo, the protagonist (and major anti-hero for a while) of Grandia II.

"Well, well. Look what the slavish devotion to sanctimonious bloodshed dragged in. What brings you here? ...or did I answer myself?

"I'm sorry, but that's not vague enough for me. Can you be a little less specific?"

I am the shadow warrior!
Be ploud mista Woo
You look like half a man you used to be! (after slicking a monster with his sword)
Whoo wanta some wang?
Aaah, better than acupuncture
I KILL YOU!
Holy pieces of cow!
Howz dat kungafoo fighting you chikina sh!t!
Syonara scumbag!
Eata dis, pencila d!ck!
Oh you littla tiny d!ck!
You are weak as a baby fart - go live in fear
You stupid!
I like nukelar wepens

And the really dirty one:

You want to wash Wang or you want to watch Wang wash wang?

I've had many bad days, but I had never woken up dead before.
(Discworld noir)

[url=http://UnEpic :]UnEpic :[/url] I see you don't know the sentence "a hole is a hole", or "when hunger comes to Dave, the ass of a corpse is no longer safe". He he, I'm going to enjoy this!! Attack!!

This game is insane.

"Idleness breeds heresy!" - Dawn of War

At least I think that's what he says. I've only played the German version of DoW and he keeps screaming "Ketzerei entspringt aus Müßiggang" and it sounds fucking *awesome*. I've not heard many Warhammer 40,000 games that have been badly dubbed into German.

<i>So what shall it be? Do you join the Unity or do you die here? Join! Die! Join! Die!</i>

<i>AGRO!</i>

Inquisitor :

The rascal is such a skillful thief that he could steal the nose between your eyes and you wouldn't notice before you wanted to blow it.

"This is good, isn't it?" -Big Boss, MGS4