Darkseid isn’t just a Superman villain, mostly because he tends to antagonize everyone in the Justice League. But it’s something about Kal-El and his goings on that apparently sets the Lord of Apokolips off. One of the most legendary battles that took place between the Man of Steel and the Omega King occurred in the superb animated film Superman/Batman Apocalypse. Watch the ending fight scene just to get a sense for how much Superman hates Darkseid.
Lex is to Superman what the Joker is to Batman. Lex uses Superman to gauge his arching skills and probably couldn’t exist if Superman were to ever vanish from the DC Universe. Somehow, some way Lex finds a way to remain a thorn in Clark’s side, whether he’s dead or alive or imprisoned. You can always count on Lex to stay ready in his pursuit of Superman’s defeat.
If adapt and react were a character, it would be Doomsday. Responsible for the death of Superman in 1992, Doomsday is known solely for being the slayer of Superman. He’s a beast that Superman has always had trouble fighting and successfully stopping, and any time he shows up, you know Superman will probably die.
Always ready to clap it up with Superman, General Zod has a superiority complex and an ego the size of Krypton before it exploded. That’s Zod’s problem: He just knew he was right and knew what was best for Krypton. Generally, that involved fighting with the House of El and it generally involves fighting Superman at some point. This is a fight that supersedes an entire planet disintegrating.
The know-it-all supercomputer is one of Superman’s most obnoxious foes. He’s known for two things: His “twelfth-level intellect” and shrinking cities down and stuffing them into bottles. Sometimes, depending on the version, he’s also known for causing the destruction of Krypton. In any version of Superman’s battles, Brainiac is known as one of his most destructive and dangerous foes.