Not really an easter egg either, but very easy to miss. In Broken Sword 1, (I know this is on the GBA, I don't remember if it was on the PC), if you left the sink in the basement running in Ireland, then George had an extra couple of lines of extra diologue when he retold the story to Nico. The diologue went something like:
George: "I couldn't sleep at all. The whole pub ending up flooding."
Nico: "Flooding?"
George: "Yeah, some moron left the running water in the basement."
I was cracking up because of course he was referring to me.
Also, the whole opening part of the game in France can be done completely out of order leading to lots and lots of alternate diologues. Some are really funny and some give a better insight to the story.
