5. 'The Batman Chronicles Vol. 1'
A foundational text for the entire superhero genre, Chronicles collects Batman's first year of adventures in order, from his creation by Bill Finger and Bob Kane in Detective Comics #27 through the debuts of his sidekick Robin and nemesis the Joker, courtesy of co-creator Jerry Robinson. You'll be surprised by how dark the Dark Knight started out – he packed heat and didn't mind killing the occasional criminal – and how quickly he transformed into the more wholesome Caped Crusader.