Ultimate Cross Over

[image error] What if every story that had ever been told was true? Imagine if all the created universes existed within our own right now, how would that play out? It would be utter chaos for a start. So let's be so terribly human and try and put some order to things. Let's start with one story: 'Twilight'.
Okay, so we have vampires and werewolves being incredibly lame and fighting over the dullest girl on the planet. Awesome. Let's add something similar, like 'Buffy the Vampire Slayer'. Now we have a whole rich universe and the outcome that Buffy would probably stake Edward within a few seconds of the opening theme tune. He wouldn't even be a major villain, he wouldn't be a funny aside, he would just be dust. Yet, remember we are talking about every universe ever created. So let's throw in Marvel and DC while we are at it. Hell, let's throw in Dark Horse as well. So there you have all manner of superheroes and antiheroes fighting all manner of monster and beastie within our own world. Pretty chaotic and probably a short sad existence with a messy end for most ordinary humans. 
There might be a few surprises along the way. Maybe the Hulk would kill some major characters, or maybe Buffy would destroy the Darkness. Then the aliens from 'Independence Day' attack... and they would probably be completely trounced by all the supernatural creatures of immense power that exist here on Earth. Smeg off back to your home planet, you stupid space weevils! Batman might be tracking down someone who he thinks is the penguin but it actually turns out to be Moriarty. The Hunger Games might be combined with the Running Man TV show and all sorts of new allegiances would be made. 
But just think about how much of this stuff takes place only in New York or LA. In other parts of the world it might be quiet. Take England for example. There might only be Sherlock going around solving mysteries committed by the old ones from 'Being Human', while Harry Potter and chums fight their evils behind closed doors, that is until the plague of '28 Days Later' comes along and quiets everyone. Then you have superhero zombies to worry about.
Which raises another good point. What storylines would be killed off completely? We've already discussed that 'Twilight' probably won't happen, but maybe none of the modern day stuff will happen because of all the alien invasions that would have happened in the 50s and 60s, but then the monsters from pretty much every story ever have existed for centuries so they would still be around to stop aliens.
Of course I've only mentioned a fraction of available stories from different media, and those to my personal taste. I cannot even begin to count the number of stories from around the globe. So let's just imagine a world in which aliens, monsters, ghosts, dragons, wizards, hit-men, gods, fairies government conspiracies, sordid love affairs, serendipity and the like actually exist. What story could you tell about that world?