Finally, we arrive at the number one factor in giving Batman the best extended universe in comics, and it shouldn't come as much of a surprise to keen DC readers. Batman has, by far, the best rogues gallery in comic books. Spider-Man has an impressive list of villains, no doubt, as does The Flash. But in terms of sheer number of psychologically captivating, visually dynamic characters, Batman's rogues win hands down. The Joker. Two-Face. Poison Ivy. Catwoman. The Penguin. Ra's al Ghul. The Scarecrow. Mr Freeze. The Riddler. Hush. The Court Of Owls. Killer Croc. Clayface. Harley Quinn. Deadshot. Man-Bat. Bane. Many of these villains are household names in their own right, after appearing in Batman movies, animations and video games. People from most walks of life will at least know who The Joker and Catwoman are, so ingrained are they in popular culture. Young gamers the world over are now familiar with the likes of Harley Quinn and Killer Croc from playing the Arkham Asylum games. Ra's al Ghul, as well as featuring in the Nolan movies, is now coming to the Arrow TV show. But aside from their uses in other media, these villains all have rich comic book history. If you want to read a chilling Joker story, check out The Killing Joke or Death Of The Family. If you're in the mood for Bane, have a look at the Knightfall Saga. Like Catwoman? Take a peek at Ed Brubaker and Darwyn Cooke's run on her self-titled comic. Fancy a story which features all the Bat-villains you could care to mention? Hush is the one for you. Every fictional hero is only as strong as the villain he is pitted against and in many ways, sometimes the villain defines the hero, and this is true for Batman. This makes his villains absolutely indispensable to the extended universe. So, what say you? Have we forgotten any great elements of Batman's extended universe? Do you agree that it is the best in comics, or do we have any Avengers, X-Men or Spider-Man fans out there that would disagree? Sound off in the comments below.