If someone else could be Batman, who would it be?

Did you guys read the 4 issue miniseries where a alternate Damien Wayne became Batman? It was good and you should check it out. 

Technically, there are several of Batman's villains that could have taken the cowl, had things gone a little differently.

The Joker is both brilliant and physically capable enough to do it, and while he would be a more low-tech Batman(due to not having the same resources as Bruce Wayne), he would likely have excelled in a different way.

Edward Nigma, while not as physically capable, could easily have taken up the cowl, to prove his intellectual superiority to the criminal underworld.

Hush, just like Bruce, could easily have ended up a vigilante, if he had been the center of events, rather than Bruce.

Harvey Dent also has the potential, both physically and in terms of resources, though less so in terms of his intellect.

Going with a younger version, Tim Drake seems like the obvious choice. The one person that has, according to Bruce himself, surpassed the Bat as a detective. With the right backing, he would be a brilliant Batman.

What was it called? I must try to see this immediately!