Stop hitting him! He’s a friend!
Smash TV, isn’t it?
Here’s one of my contributions:
“Get the heck out of here, you nerd!”
Okay, not really spoken, but read.
Nope; it’s Secret of Mana (Seiken Densetsu 2).
Arkanoid.
No one needs to answer mine due to slam dunk easyness, but I also haven’t seen it mentioned yet. I’ll still post them as they are the best old video game quotes ever:
Dwarf needs food – BADLY!
Green Wizard is about to die!
Yup 
**The dwarf throws a nasty little knife at you, but misses !
In addition to dressing like a woman, it seems you like to smash and grind things.
Behold ! The Flame of Judgement !
**
Adventure!
Correct !
Final Fantasy Tactics ?
Zork II
Here’s a few:
**
“The hands sail off into the distance.” (bonus if you know what causes this to be said)
“The troll disarms you. Luckily, you still have your sword…”
“You exit the sauna a changed man. You are carrying a changed plant.”
“Ooh! Are we gonna do something dangerous now?” (bonus if you know what causes this to be said)
**
Toasty!
You pick up Tea. You pick up No Tea.
What’s that? Oh, it’s just a bush with a large nose.
I’m selling these fine leather jackets.- TWO games this has been in, please! (there’s more than two, though, i’m sure)
First one sounds familiar.
Second is from The Hitchhiker’s Guide to the Galaxy.
Third one sounds familiar.
Fourth one doesn’t.
Oh No! is from Lemmings.
It wad first in “Indy and the Last Crusade-The Graphic Adventure game”. It’s been in a number of Lucasarts games since.
“Delta one-niner, mayday, we are lost behind Jupiter!”
“Roger, this is delta one-niner, we have you on radar and are go for hyperspace!”
These quotes are taken from memory, so please don’t hit if they’re not quite right.
Video game:
“Oh, thank goodness! I’m back to my old self again!”
Computer game:
“Don’t be silly!”
More Video Game:
“Killin’ a person ain’t no big deal. Just put a gun to their head…pow.”
More Computer Game:
“I tried so hard to picture her in my mind. Put her down on paper as if that might bring her back. I couldn’t do it. <Name>, I’m not you.”
Fallout? Or Fallout 2?
I remember playing a demo of a game where the player awakes from his grave and utters these words at the very start. It also includes the line “IT BURNS!” when you set an enemy on fire 
Here are two of my own;
“That was left handed”
&
“Keep 'em coming.”
Same character, same game 
Oh, one other;
“Entaro Adune”
Although the exact spelling escapes me, its phonetically correct 
Beach Head II
I loved that game.