3. The Motherf*cker Dies - Kick-Ass 2
One of the big things that irked people about Kick-Ass 2 was that the character of Chris DAmico - who, under his supervillain guise "The Motherf*cker," is a force of unabashed evil in the film - survived. Kick-Ass 2 ends with a huge fight sequence, where he's bitten by a shark and left to die. But he doesn't: he loses his legs and his penis, but he's alive. In the original draft, however, that wasn't the case: writer Mark Miller also thought that Chris should die at the end of the movie, because he'd finally pushed things way too far. That's when writer Jeff Wadlow got in touch with Miller and changed his mind:
"I emailed Mark and asked, 'What are you doing?! You cant kill Chris. Arent you thinking of a third one? Werent we talking about a third movie we cant do it without Chris - hes a corner of the triangle.' Mark was like, No hes such a bad guy, hes gotta die. And I said, No, no, no, no figure it out. You can punish him for being bad, maybe he loses his legs or something like that - but hes gotta be alive in the end.'"
Thing is, Kick-Ass 2 was deemed to be such a failure that Kick-Ass 3 probably isn't going to end up being made. So now Chris, the terrible human being that he is, is unlikely to ever get the comeuppance he deserves.