5. Darkseid
My personal favorite villain of all time, the ruler of Apokolips is the ultimate antagonist. Darkseid is a god who only seeks one thing, to control all living things with the anti life equation. In his quest to find it, he makes Superman's life a living hell. Darkseid has no moral compass which makes even more of a threat. He has manipulated many of DC's top heroes and has even warded off some of DC's most powerful villlains, including Brainiac. His powers include inescapable omega beams, super human strength, speed, stamina and is nearly invulnerable. He's also a telepath, telekinetic, can alter his size and can teleport himself. Oh and he's considered a new god which makes him immortal in today's comics.
His Weakness? Like any other super villain, it depends on who's doing the writing but he has been defeated by Superman's pure power, however he wasn't killed. Darkseid was also hurt by Doomsday's protruding bones in one addition of the comics. Willpower can also be considered a weakness considering it takes a great deal of it in order to perform most of his powers so if his willpower gets rattled, he becomes weakened. He can also be affected by a substance called radion which seems to be a mystery to most. Although it'd take an abnormal amount in order to affect him.