In God of War 1, there was a statue at the end of the game that you could destroy with a special jump attack..
Then you got some funny artwork scenes whilst Kratos was talking about how he thinks you has cheated to find this easter egg.. Also some other funny things he said but it is a long time since i played it now so cant remember..
Also, there was a easter egg in one of the first GTA games for PS2, where you could stack cars on top of each other to climb over a wall, and there was a text on the other side of the wall saying "You are not supposed to be here!"
And in Leisure Suit Larry 7, love for sail, there was many easter eggs making it posible to see the boobs of the women you were talking to.. hehe..