Who are all of Superman's enemies?

Lex Luthor: Superman's most well-known enemy. Pre-Crisis, Luthor was a rogue scientific genius with a personal vendetta against Superman, using his scientific prowess to destroy the Man of Steel by any means possible. Post-Crisis, Luthor is portrayed as a powerful but corrupt CEO of a conglomerate called LexCorp, but still has the same hatred of Superman. Recently, his public downfall has resulted in him returning more to his pre-Crisis persona. Actors portraying Lex have included Gene Hackman, John Shea, Clancy Brown, Michael Rosenbaum and Kevin Spacey.

Darkseid: A cruel and merciless alien who rules the planet Apokolips and only deals with Superman when it benefits his own agenda. Not originally created as a Superman villain, but by Jack Kirby for his New Gods series.

Bizarro: An imperfect duplicate of Superman. Pre-Crisis, Bizarro was created by an imperfect duplicator ray; post-Crisis, he originally was a failed experiment of Lex Luthor's. More recently, a newer version similar to the pre-Crisis version was reintroduced.

Metallo: A cyborg criminal who prefers using kryptonite as his power source, which makes him a deadly threat to Superman.

Mongul: An alien tyrant, notable as one of the few villains to be as strong as Superman. Mongul aided the Cyborg Superman in his attempt to turn Earth into a new Warworld.

Mr. Mxyzptlk: A being from the fifth dimension with magical powers who delights in tormenting Superman and traditionally could only be made to return to his native dimension by being made to say or spell his own name backwards.

Brainiac: An alien scientist from the planet Colu, intent on conquring Earth; pre-Crisis, Brainiac was portrayed as being an android. Post-Crisis, he was portrayed as a circus mentalist named Milton Fine who was possessed by a Coluian intelligence. During "The Doomsday Wars" storyline, however, Fine's body was destroyed and Brainiac once more inhabited a robotic body.

Phantom Zone criminals: Pre-Crisis, these were Kryptonian criminals imprisoned in a dimension called the "Phantom Zone", in which they only existed in a ghostlike form; this allowed them to survive the destruction of Krypton. Various such criminals would sometimes escape and attack Superman.

General Zod: Pre-Crisis, Zod was one of the main Phantom Zone criminals that fought with Superman. Post-Crisis, Zod was first depicted as a Phantom Zone criminal that Superman encountered in an alternate dimension; eventually, this Zod was killed by Superman with kryptonite. A second version of Zod was later introduced as a product of Soviet genetic engineering, surgically altered to mimic Superman.

Parasite: A janitor (Maxwell Jensen pre-Crisis; Rudy Jones post-Crisis) who had been mutated into a super-powered man who could absorb the powers, strength, and memories of any organic being, and wanted Superman's power for himself.

The Prankster: A villain who uses various practical jokes as a motif in his crimes. His real name is Oswald Loomis.

Terra-Man: Pre-Crisis, a cowboy-dressed villain who uses various high-tech weapons digusised as those of the American Old West.
Intergang: A nationwide organized crime syndicate armed with weapons supplied in part by Darkseid.

Doomsday: A mindless, impossibly powerful, raging monster that killed Superman during the Death of Superman storyline. During the Last Laugh storyline, a "jokerized" Doomsday that had been reengineered with changes from Superman's DNA attained intelligence; Darkseid and Luthor apparently had a deal to make clones of Doomsday. A version of Doomsday seen recently attained more than just the ability to talk, but the ability to reason and experience emotion, which ultimately turned him from an evil monster to a hero that saved Superman in the present and in an alternate future.

Imperiex: An all-powerful force of nature whose purpose is destroying galaxies. Eventually, Superman, Steel, and Darkseid stopped Imperiex by using Doomsday as an ally, along with a powerful weapon called the Entropy Aegis.

Toyman: An insane criminal who uses special equipment and weapons based on toys.

The Cyborg Superman: A reanimated astronaut cyborg who briefly impersonated Superman after his death, and also destroyed Green Lantern Hal Jordan's home of Coast City.

Effron the Sorcerer: A sorcerer who came from the magic kingdom of Veliathan and controlled a faceless puppet army.

Gog: A human from the future who masters time travel, and hates Superman for allowing his parents to die.

Preus : Formerly a law enforcement officer from the bottle city of Kandor, he escaped the city and hunts Superman.

Ultraman: An evil counterpart of Superman from an alternate Earth, Ultraman possesses powers similar to Superman's. Post-Crisis, Ultraman's power source is through exposure to Anti-Kryptonite instead of his Earth's yellow sun. Ultraman is a member of the Crime Syndicate of America, a villainous version of the Justice League indigenous to his universe.

The Kryptonite Man: Pre-Crisis, a criminal with space-acquired kryptonite radiation powers; post crisis, similar but originated as a clone of Superman or in an experiment with kryptonite .

http://en.wikipedia.org/wiki/Enemies_of_Superman