"Didn't we have some fun, though? Remember when the platform was sliding into the fire pit and I said 'Goodbye' and you were like 'No way!' and then I was all 'We pretended we were going to murder you'? That was great!" -GLaDOS; Portal
Oh boy, GLaDOS really cracks me up. This is probably the funniest thing she has ever said, in my opinion. I found myself playing through Portal and Portal 2 just to hear what she'd say next.