10. Superman Says His Real Name In Front Of The Joker
The Injustice comics are directly inspired by the video game franchise, Injustice: Gods Among Us. The story takes place in a parallel universe where Superman has gone insane after the Joker tricked him into murdering Lois Lane while she was pregnant.
In Injustice Year 3 #13, Batman exposes Superman to Black Mercy; a parasite that lulls the host into a deep sleep. While knocked out, Superman has a dream that he is about to kill Lois before Batman alerts him he is being manipulated by the Joker. Enraged, Superman strides towards the wicked jester, preparing to put him out of his misery.
Batman tries to stop him, which causes Superman to shout, "Stand aside, Bruce." The Joker smiles gleefully (more than usual), realising that he now knows Batman's real name.
As awkward as this confrontation is, it gets worse. Believing the Joker knows too much, Batman panics and breaks his neck! The story may take place in a dream, but it's still a great moment as readers have always wondered what would happen if Joker learned of his nemesis' secret identity.