Portal

You know, being Caroline taught me a valuable lesson. I thought you were my greatest enemy, when all along you were my best friend. The surge of emotion that shot through me when I saved your life taught me an even more valuable lesson – where Caroline lives in my brain.

GLaDOS

Most test subjects do experience some cognitive deterioration after a few months in suspension. Now you've been under for... quite a lot longer, and it's not out of the question that you might have a very minor case of serious brain damage.

Wheatley

The best solution to a problem is usually the easiest one. And I'll be honest - killing you is hard.

GLaDOS