3. Luthor
The old adage 'a hero is only as good as his villain' is well apt for Lex Luthor. He's one of the smartest men on Earth and believes the human spirit can accomplish anything. No goal cannot be accomplished when the mind is put to it is his philosophy. So why then is Luthor an enemy of Superman if he essentially holds the same beliefs? Brian Azzarello spends nearly 150 pages in Luthor (originally called Lex Luthor: Man of Steel) examining the Man of Steel's arch nemesis. Lex is a man who fully believes he's the good guy while acknowledging the evil within him, believing everything he does is for the greater good. To him, Superman is an alien waiting to take over while stripping away mankind's independence. What can you do if you have an alien who can and is willing to do anything after all? Lex believes people will stop looking up to the sky to imagine what is possible in place of a saviour instead and desperately wants to change that. The complexity Azzarello gives him is excellent and the fact you can sympathise with and understand Luthor to an extent is a testament to how in depth he goes into the mind of Superman's main villain. The sad irony though is if he spent even half his fortune and intellect actually saving the world rather than combating Superman, he might do more good than his rival.