Also some of my favourite lines:
"Oh, you think you're doing some damage?! 2+2 is... 10... IN BASE FOUR! IM FINE!"
"Don't believe me? Here, I'll put you on: 'Hellooo!' THAT'S YOU! THAT'S HOW DUMB YOU SOUND!""
"Look - we're both stuck in this place. I'll use lasers to inscribe a line down the center of the facility, and one half will be where you live, and I'll live in the other half. We won't have to try to kill each other or even talk if we don't feel like it"
GLaDOS is awesome