Superman is distinct among superheroes as one of the most upstanding role model figures in fiction. That is precisely why so many find the story of an evil Superman so compelling, imbued with a terror at seeing this god-like being turn against humanity or a tragedy at seeing this hero among heroes become a villain.
There have been times in the comics where, either of his own free will or the manipulations of a villain, Superman changed from the world's greatest hero to a terrible enemy. DC's many great writers have done this concept justice in many excellent and fascinating stories that play with the concept in unique and creative ways.
Batman: Hush (2002)
The Batman classic by Jeph Loeb and Jim Lee saw Batman and Catwoman at one point investigating Poison Ivy, tracking her to Metropolis where they discovered the villain had brainwashed Superman using her newly Kryptonite-infused plant powers. Always prepared, Batman invoked his handy Kryptonite ring to defend himself from the attacking Superman in a tense chase, pulling out all the stops to stay alive.
The Man of Steel was liberated from Poison Ivy's control by the timely intervention of Catwoman dropping Lois Lane from the Daily Planet building. His love for Lois kicked in, overriding his orders and saving her, which broke Ivy's influence. While brief, it was a scary moment when the most powerful superhero of them all suddenly became the minion to one of Batman's rogues. With morals to restrain him, Superman became one of the Dark Knight's most terrifying, and powerful, villains.
Blackest Night (2009)
One of the biggest DC events of all time, Blackest Night saw the rise of the Black Lanterns, powered by death itself. Dispatching black rings of power to the limitless dead and reviving them as zombies. It was a dark period in which many of DC's long-dead characters returned from the grave as zombies to battle the living, and it was both terrifying and amazing.
However, the ranks of Nekron's undead also included those who were killed before and revived, including Green Arrow, Wonder Woman, and yes, Superman. Seeing the Man of Tomorrow -- controlled by a black ring as a zombie servant of a terrible new villain was a horrific highlight of the comic, but the combined forces of the entire DC universe saved the day in the end. Perhaps the most disturbing element of all in this evil Superman appearance was his appearance. With his flesh decaying and jaw fully exposed, zombie Superman was a terrifying sight for heroes and fans to behold.
Superman/Batman: Absolute Power (2005)
When supervillains from the future travel back in time to kill the Justice League of America, they acquire a young Clark Kent and Bruce Wayne, raising the two boys into supervillains. Superman and Batman become the world's greatest threats, every bit as strong and resourceful, yet totally devoid of the moral fabric that made their prime versions the iconic heroes they are.
Perhaps best of all, the story is canon, and requires the heroes to make some repairs to the ruthlessly damaged timeline, but consequences remain that keep this story a meaningful chapter in the history of these two iconic superheroes. It is a unique twist on the unlikely Batman and Superman duo, somehow maintaining a friendship between the two heroes-turned-villains as they travel through different timelines together.
Superman: Doomed (2014)
The legendary Superman villain Doomsday never killed the Man of Steel in the New 52 continuity. Instead, in an arc written by Greg Pak, Charles Soule, and Scott Lobdell, audience expectations are subverted when, after Doomsday emerges from the Phantom Zone to rampage across the world, Superman kills the beast only to become infected with a virus that transforms him into the apocalyptic monster himself: "SuperDoom."
This massive epic turns Superman into the greatest threat to the DC Universe, a mindless rampaging monster who is almost unstoppable. Not only that, multiple major villains like Brainiac and Mongul intervene to exploit the chaos, upping the stakes even further as the remaining heroes find themselves fighting on too many fronts to protect the Earth. It is arguably one of the most intense arcs of the New 52.
Superman: The Dark Side (1998)
John Francis Moore and Kieron Dwyer created this story where baby Kal-El's spaceship landed on the worst planet possible: Apokolips. There, Superman's most evil villain, Darkseid, raised Kal-El as his own son, conquering worlds in his name. It is not all doom and gloom, however, as this Superman has a spark of redemption within him that holds a promise of hope in this dark alternate world.
This story was even loosely adapted in the Superman: The Animated Series episode "Legacy" (2000), where Darkseid captured and brainwashed Superman into believing he had been raised on Apokolips. It was the darkest chapter of the series, ending it on something of a downer, but it led into the more optimistic Justice League (2001) series where Superman's conflict with Darkseid persisted.
Superman: Sacrifice (2005)
In a multi-issue crossover event written and illustrated by a team of DC's finest, Maxwell Lord brainwashed Superman by distorting his perception of the world, making him see Batman as Brainiac and Wonder Woman as Doomsday. Famously, he brutally beat the Dark Knight to near death, but Wonder Woman ultimately saved them both in a controversial move.
While not "evil" per se, the Man of Steel became a powerful enemy displaying how mean Superman becomes when he believes the people he loves such as Lois Lane have been killed by heartless supervillains. To be on the receiving end of that wrath made for a terrifying story while simultaneously giving Wonder Woman a chance to save him from himself.
Superman: Red Son (2003)
What if Kal-El's spaceship had landed in the Soviet Union? That is the question of Mark Millar's Elseworlds story. Raised a communist loyal to the Soviet state, Superman takes control of his new adoptive country to expand a seemingly utopian reign across the globe, all while Lex Luthor opposes his rule from the United States. Spanning decades, the epic story could have been a multi-year series in its own right.
Though part of what makes this take so fascinating is that Superman is not irredeemable. Though he is a conqueror, he is driven by genuine compassion from start to finish, to the extent that some fans of this famed classic do not even consider him "evil" per se. Not only that, his Lex Luthor is basically the "good guy" of the story despite his moral imperfections and is depicted as one of the smartest iterations of the character.
Injustice: Gods Among Us (2013)
The underrated thorn in Superman's side the Joker used Kryptonite-laced fear gas to make the Man of Steel hallucinate Lois Lane, pregnant with his child, like Doomsday. Not realizing the truth, he punched her into space where her heart stopped, triggering the nuclear device in Metropolis that destroyed the city. This was the first domino that started Superman down the path of becoming a dictator.
After executing the Joker, one event after another further radicalized Superman towards villainy, joined by multiple sympathetic heroes lured over to his cause. It is a powerful, tragic journey from the start to the present. Filling the gaps of a narrative that began with the game Injustice: Gods Among Us (2013), the comic series is the definitive story of a Superman who lost his way. Most troubling of all is how the audience's sympathies still remain somewhat with the Man of Steel. His loss of Lois, and his accidental role in her death, is always present even when the former hero is doing terrible things burning Martian Manhunter alive.