DC Comics is one of the two mainstream comic distributors in the world (the other, of course, being Marvel Comics). They publish dozens of titles and have invented thousands of characters. Warner Brothers acquired DC and strengthened their film department. Unlike Marvel Studios, Warners has all the DC characters legally under one umbrella. This allows them to (theoretically) assemble a film universe encompassing all DC heroes, from the fan favorites to the obscure, with ease.
Christopher Nolan was certainly an asset in rebuilding the DC film-verse after those Joel Schumacher Batman films happened, and below we celebrate Nolan's films, along with all of the others that gave us faith in DC's larger than life heroes once again. They taught us that a man could fly, that bats really were frickin' scary, and that we really should remember, remember the fifth of November.