"Stay Awhile and Listen:" - Deckard Cain Diablo series

And a 2nd one:

"I go long!" - random CS GO player on Dust2 map:D

"The KingMaster always wins" - True Crime. Streets of LA.

"The Computer Is Your Friend. The Computer wants you to be happy. Happiness is mandatory. Failure to be happy is treason. Treason is punishable by summary execution." - Paranoia, a role-playing game.

Ezio don't you recognise me ? It's me Mario.

Cousin, let's go bowling - Roman

"Inhale my dong enragement child" - Freddy, Five Nights at Fuckboys

"Lady got a gut full of dynamite and a booty like Poww!!!"
"I Have the shiniest Meat bicycle!!"
"I'm the conductor of the Poop train!"
"BURN ALL THE BABIES!!!!"

• All from Borderlands 2, and amazing game of awesomeness

"It seems like Garrus has finally worked that stick out of his butt, but now he's trying to beat guys to death with it" - Jeff "Joker" Moreau Mass effect 2

couldnt stop grinning for roughly 2 hrs after hearing that

"Another visitor. Stay awhile, stay forever!" Elvin Atombender in Impossible Mission (Commodore 64-1984)

"You are irrelevant" - The Fall.
"You wanna piece of me, boy?" - StarCraft Brood Wars marine spawn.
"Ashes to ashes, motherf@cker!" Metal Gear Rising.

What is a man? A miserable little pile of secrets.

"Insanity is doing the exact... same fucking thing... over and over again, expecting... shit to change" -Vaas, Far Cry3

"Do you feel like a hero yet?" -Konrad, Spec Ops The Line

"What can change the nature of a man?" - Ravel, Planescape: Torment

"I will, help secure the release of your college. But help, has a price "
by the dentist for payday 2 on hotline Miami mission

Lesbomancy, my favourite type of magic (Witcher 2)

"Pick up the moon? Are you nuts?!" Escape from Monkey Island (if you try to make the character pick up the moon obviously :P)

"You chose the road, old friend. God put me at the end of it." -Templar (PoE)

Requiescat in Pace,bastardo..

"F.K. ... in... the coffee"

-I was born two months premature. When I was one, I was dropped on the porch. When I was two, I had pneumonia. When I was three, I got the chicken pox. When I was four, I fell down the stairs and broke six ribs. When I was five, my uncle was decapitated by watermelon. When I was seven, my parents hit me in the head with a shovel. When I was seven, I lost my right index finger to my pet rat. When I was eight, my dog Spike got hit by a tractor. When I was nine, my mother lost her arm to a rabid brahmin. When I was ten, my sister was torn to bits by a pack of dogs. When I was eleven, my grandfather killed himself, because I was ugly. When I was twelve, my grandmother killed herself, because I was ugly. When I was thirteen, my father poked out his eyes with a pitchfork in a drunken stupor. When I was fourteen, my brother lost his hand to a wallaby. When I was fifteen, my aunt choked to death on a chicken bone. When I was sixteen, I lost my cousin to a badger. When I was seventeen, I cut off my left big toe with a hoe. When I was eighteen, my father lost his right leg to the same tractor, that killed my dog. When I was nineteen...
-Oh, I get the picture. What's currently bothering you?
-Well, there I was, traveling through the desert, when suddenly my brahmin falls over dead. About then I relized I was low on water and hadn't had a drink in quite a while. Later, my bones began to ache, my head started to hurt. Well, there I was sitting in the desert, waiting for the world to swallow my miserable existence, when a pack of deathclaws shous up. Well, I'm thinking to myself, this is it. Now I can die. I can wind up as a pile od deathclaw shit in the middle of the desert. But no... fate had yet another cruel card to play against me. You see, the deathclaws didn't kill me. Instead they gave me water, brought me herem gave me this room, gave me food, cleaned me up, and now they won't me leave. I know they're fattening me uo for some unknown, horrible fate. I keep telling them that I would probably taste better if i was leaner but it does no good. They just smile -- if you can call it that -- and pat me on head and say 'don't worry human, thinks will be better.' Ha! We both know what that means. Anyway, to make matters worse, then they started giving me some sort of medication. It was making me gassy, so I stopped taking it -- and it's a good think I did. I think it was some sort of 'mind control' pill, because I started to feel, like things weren't actually bad as I thought! Anyway, that's about it. I'm just waiting for the dinner bell to chime, so that they can feast on my bloated body.
-Please tell me that you don't have any children.
-Nope. When I turned twenty-two this strange fungus started to grow on my test...
-Stop! I don't want to know!

Vault 13 resident dialogue with the Chosen One

"Who said I did?" - Captain Martin Walker in response to the question "How did you survive all this time?" - Spec Ops: The Line

Portal has so many great quotes :p