4. Darkseid
Created by comics legend Jack Kirby, Darkseid is essentially a superpowerful god-like version of Hitler ruling over his version of Nazi Germany, Apokolips. Darkseid is also one of the most powerful characters in the DCU who has been the super-villain behind numerous story arcs, most notably Final Crisis a few years ago. Shooting Omega Beams out of his eyes, he killed Batman in the finale of the mini-series or did he? In fact the beams sent Batman hurtling backwards in time with Bruce eventually making it back to the present after several stops along the way. Final Crisis also shows how abstract Darkseid's goals can be as he tried to enslave everyone on Earth by turning them into mindless citizens like the Apokolips populace, chanting "Darkseid is..." using the Anti-Life Equation on humanity (supposedly mathematical proof of the futility of living). Darkseid's enormous power means only a handful of characters can challenge him, like Superman and Orion, which does make him formidable and he has a striking appearance. His face was allegedly modelled on the actor Jack Palance while his outfit looks like a blend of ancient Egyptian and futuristic Sentinel-chic. His outlook is straight up evil. There's no reforming this guy, nothing to make him a good person he is and always will be one of the most evil beings in the universe. And he's just fine with that, as are we as readers. He shows up, we know bad stuff is about to go down, especially when he's smiling that creepy grin. Darkseid is... a great super-villain!