Easter eggs in video games, ever found one? It doesn't necessarily have to be an Easter egg, a bug will do, though not the kind you see in games such as Duke Nukem Forever, rather something unusual, something game changing.

Speaking of Duke Nukem Forever, this game has huge list of references, though I'm not sure if they're worth mentioning as they're quite easy to find.

I remember finding PDA in Doom 3 with all the names of developers and some of their comments. It was cleverly hidden near the end of the game, you had to press a small button with id's logo on it, a completely new room would open with formentioned PDA in it.

There was also that hidden level in Warcraft III, you had to click on sheep's I think, but in certain order to unlock it.

Not sure in which version of Final Fantasy IV, GBA I think, there's a pub with all the developers in it, well, almost all.

As for bugs, while going through Final Fantasy III, full translated rom for NES, my Knight suddenly gained a level after every battle. In other words, I had maxed Knight rather early in the game.