10. Unmasking The Arkham Knight - Batman: Arkham Knight
It should've been one of the defining moments for the entire superhero genre - the first time we'd played a global game of "Guess who?", all the while being convinced that Rocksteady were going to unveil an entirely new character (as they repeatedly stated they would), or at least someone very interesting from Batman's past.
Instead... it was Jason Todd - otherwise known as "The most obvious choice since day one". Worse still, the very first thing the Knight says is "Time to die, old man", narrowing the options entirely to either Todd or perhaps Damien Wayne, at a push.
Cue the game providing a crash-course in Bruce's past with Todd (something never even mentioned or hinted at before) and an unmasking scene that had fans screaming, "Seriously?!", before a repetitive 'Sneak up and punch him' boss fight ended the encounter on a spectacularly flat note.