Here's a few of mine:
In the game "Dungeon Keeper 2", if you played it late at night (or set your clock ahead), it would start making fun of you. Some of the quotes from the 'narrator' were:
Due to your late night digilence, you've uncovered a secret gaming tip... GO TO BED!
There is a large retangular object in the room next to you which is said to have restorative powers... why don't you use it?
Your dungeon is bit on an incline! Angry monsters can't play marbles!
Your dungeon is lumpy! Order your monsters to jump up and down!
The best part is that you are so tired, you think you just imagined the guy saying it. Really takes you off guard.
Can't forget Minsc:
Stand and deliver! So that my hamster may get a better look at you!
Full plate and packing steel!
Damn. I had a bunch in my head, but I'm drawing a blank. Anyone else got some?