One of the most important moments in the history of the DC Universe was when Jonathan and Martha Kent discovered a young Kal-El and took him into their home. Raising him as their son, they helped him become the greatest hero in the galaxy, Superman. However, things could have been far different if someone else had adopted him instead.
In several of DC's Elseworlds alternate realities, Superman didn't end up being taken in and raised by the Kents. Even if his upbringing was different, these worlds all showed just what kind of person Kal-El would become without Ma and Pa Kent.
JUSTICE LEAGUE: THE NAIL
In the world of Justice League of America: The Nail by Alan Davis and Mark Farmer, there was a nail on the road in Smallville, which caused Jon and Martha Kent to pop a tire while driving. This kept them from coming across baby Kal-El, which left room for an Amish couple to discover him instead. They raised Clark with the mindset to not interfere with the world at large, which prevented Clark from ever leaving Kansas and becoming Superman. Without his presence, the DC Universe grows far more suspicious of the growing superhero population. After the death of Hawkman and the paralyzation of Green Arrow at the hands of Amazo, metahumans are either captured or killed by forces working for Metropolis Mayor, Lex Luthor.
Meanwhile, the Joker murders Robin and Batgirl during a massive breakout, which compelled Batman to kill him, and similar tragedies befell the world's remaining heroes. As violence continues to break out all around the world, Lois Lane discovers that Deputy Mayor Jimmy Olsen had captured Luthor and put him into a fudge state after becoming empowered with Kryptonian DNA. While fighting the Justice League, Olsen ends up in an Amish community and uses his powers to try and kill a farmer. The farmer survives, however, and reveals that he's Kal-El. Olsen slaughters his parents in a rage, which forces a fight between the two that ends with Jimmy dying from his powers overloading his body. Superman joins the Justice League and is taken in by the Kents, who had started to harbor fugitive runaway metahumans in this reality.
SUPERMAN: SPEEDING BULLETS
In Superman: Speeding Bullets by J.M. DeMatteis and Eduardo Barreto, the ship containing Kal-El landed in another major DC location, Gotham City. In that dark metropolis, Kal-El was found by Thomas and Martha Wayne. After naming their child Bruce, the pair raise him in a loving and wealthy home. When the pair are killed by a mugger, Bruce's powers emerge and cause Bruce to accidentally use his heat-vision for the first time and kill the mugger. Bruce goes into self-imposed isolation, hiding in Wayne Manor while his powers develop. After he eventually uses them to save Alfred from a group of robbers, Bruce learns the truth about his origins from Alfred and is shown the rocket that carried him to Earth.
Deciding to fight all of the crime and corruption across Gotham that his enhanced senses have attuned him to, Bruce becomes the Batman. Meanwhile, Lex Luthor ends up moving operations to Gotham in an attempt to take over Wayne Industries, but Bruce prevents the buy-out. When Lois joins the staff of the Gotham Gazette, she's initially impressed and attracted to Bruce. But after seeing how brutal he is as Batman, she's horrified instead of inspired. After battling a Joker-esque Lex Luthor, Batman is convinced by Lois to become something different, a figure that can inspire hope in Gotham instead of fear. Bruce gives up being Batman and transforms himself into Superman.
SUPERMAN: THE DARK SIDE
In the world introduced in John Francis Moore and Kieron Dwyer's Superman: The Dark Side, Jor-El's intentions to have Kal-El arrive on Earth are upended by a Boom Tube that sends him to Apokolips, where he's raised as Darkseid's son. Superman proves himself in combat by killing Kalibak, his adopted brother. This catches the attention of Barda, and prompts Scott Free to not wait for her. Mister Miracle escapes the planet, but Superman breaks his legs in the escape. This also allows Darkseid to openly wage war on New Genisis, with Superman deploying a bomb at the core of the world and destroying it. Highfather teleports the remaining New Gods to Earth to try and stop Darkseid from finding the Anti-Life Equation. However, Highfather remains and reveals the truth of Superman's origins before dying.
Superman is teleported to Earth and ends up roaming the streets of Metropolis until he's found and calmed down by Bibbo, Jimmy Olsen, and Lois Lane. When Darkseid travels to Earth, he reveals that the Anti-Life Equation was embedded into Kal-El's DNA. After unlocking it, Darkseid and his forces conquer the Earth with relative ease. Superman eventually breaks free and shares a kiss with Barda before heading off in a bid to bring down Darkseid once and for all.
Many of the New Gods are killed in the final battle against Darkseid and his lieutenants, but the heroes still managed to bring down the broadcast tower forcing the Anti-Life Equation across Earth. With a boost from a mortally wounded Lightray, Superman was able to defeat Darkseid. Mister Miracle returned to the stars, leaving Orion and Superman to pick up the pieces of society. New Genesis joins Earth and Orion becomes High-Father alongside Lois. Meanwhile, Superman helps liberate Apokolips and turn it into a more natural planet alongside his love, Barda.