2. The Arkham City Room
The best Easter eggs are always the ones left hidden for years after the release of the game. The secret room in the wardens office of Arkham Asylum is one of those eggs. Even if you've played Batman: Arkham Asylum through and through, got 100 percent clearance, and unlocked all of the achievements or trophies, you still probably haven't found Warden Sharp's secret room right off of his office. It's not located on any of the maps. You can't see the weak wall with Batman's detective vision. And you can only blow it up with several applications of explosive gel. Open that room and you'll fine maps and blueprints and charts depicting plans that tie into the sequel Batman: Arkham City. Mind Blown #1: fans of the series could have realised what the sequel was about even before it was announced. Mind Blown #2: It went undiscovered for over six months and the developers Rocksteady had to announce that the Easter egg actually exsisted. But, in the this world of secrets that made my jaw hit the floor, there is only one that beats it.