Lois Lane

Earth-Two
It was revealed that later, he revealed his dual identity to her, and the two were married. Although fully grown, Power Girl became a surrogate daughter to the couple.
 * 1)  Clark Kent / Superman  - The Golden Age Superman is shown to only have eyes for Lois Lane. He played the goofy, clumsy nerd as her co-worker Clark Kent, while she swooned at Superman. She would often suspect the two were one and the same, but he would always find a way assuage her suspicions.

When Earth-Two was destroyed in the Crisis, Clark, Lois, and Power Girl were the only three survivors. Clark and Lois went off to live with Alexander Luthor and Superboy-Prime in an alternate dimension Luthor had created, where they watched the new world of heroes grow.

Eventually, that world took some dark turns, with heroes making some questionable decisions. Lois began to grow ill.Clark attributed it to the growing darkness in the outside world (like that makes sense). He concocted a plan to try and change the reality of that world with Alexander and Superboy. Before he could accomplish anything, Lois died. He later learned that Alexander and Superboy had made Lois sick, in a scheme to have Superman help him change the world to their liking. He then battled Superboy Prime in a fight that resulted in his death.

Earth-One
As an adult, Lana Lang moved to Metropolis and became a reporter, and had much the same relationship with Superman, with her and Lois becoming “rivals” for his affections (though I’m not sure how much rivalry, or even romance, was ever really hinted at)
 * 1)  Clark Kent / Superman  -  Lois and Clark had much the same relationship as their Earth-Two counterparts. He was a nerd, she loved Superman, but was often trying to prove that he and clark were one and the same.

2.  Biron / Comet / "Bronco Bill"  - "Bronco Bill" was secretly an ancient centaur who had been cursed to the form of a horse, but could take the form of a human whenever a certain comet passed over. He performed as Supergirl's superheroic pet horse Comet. When in human form, he often romanced Supergirl, and even did so for Lois Lane multiple times.

Post-Crisis/New Earth
During this time, Lana Lang came into Clark’s life as an adult for the first time six years into his career, thus eliminating her as a competitor in the early years. Lex Luthor, for his part, had Lois as an object of his affections; affections which she continually rebuffed.
 * 1)  Jeb  - A love interest some time before Superman came along.
 * 2)  Clark Kent / Superman  - In Post-Crisis stories, though, Clark is shown as having forgone the nerdy cover, and engages Lois as an equal. However, many of those old Earth-One stories, with him acting that way, are technically still in continuity. Also later stories that took place during that time (like “Trinity”) showed Clark still using his nerdy motif with Lois and others, so that aspect seems to have been written back into those times. Nevertheless, into the present time, they were able to grow closer than before.

3.  Jose  - A love interest after the events of Gang War.

Eventually, with Lois still unaware of his dual identity, she lets go of her crush on Superman and begins dating Clark. He reveals his dual identity to her at the same time that he proposes. She accepts, and they are later married.

New 52

 * 1)  Clark Kent / Superman  - I assume there is still the good-ol’ tension with Lois in New 52.

Earth-Three

 * 1)  Lex Luthor  - In this world, where all the superheroes of Earth-One were supervillains and Lex Luthor was the world's only superhero, he and Lois fell in loved and were married. They had a son togetehr, Alexander Luthor. When Earth-Three was being destroyed by an anti-matter wave, Lex put their son in a special experimental craft able to travel between dimensions, sending him to safety. Lex and Lois embraced as the wave engulfed them.

Kingdom Come

 * 1) Clark Kent / Superman - In The Kingdom Come world, Clark was very much in love with Lois, who died tragically.

All-Star

 * 1)  Clark Kent / Superman  - Lois remains the love interest of Superman in the All-Star world.

In General
Clark is shown with the same typical relationship with Lois (they’re co-workers, and as Superman he saves her a lot) in the radio show, the Fleischer cartoons, the 1948 and 1950 film serials, the 1950s television show, and any animated television version, although romance is not typically a focus in this early material. The same relationship also permeates any direct-to-video animated film.

1978-1987 Film Series + Superman Returns
In the second film, Lois learns his true identity, and the two form a relationship. Clark is told by the essence of his mother in the Fortress of Solitude that if he wishes to be with a human, he must become a human. Using the Fortress’s technology, he does so. But then the Kryptonian villains, Zod, Ursa, and Non attack Earth, and he is forced to gain his powers back to stop them. After this, he and Lois realize they cannot continue in their relationship. Using a bizarre new power, Clark kisses her and, through the kiss, erases her memory of his true identity and their time together.
 * 1)  Clark Kent / Superman  - Clark immediately falls for Lois after moving to Metropolis. She immediately falls for Superman. As Clark, he manages to get her to go on a date with him, but also arranges it so this happens immediately after she has an exclusive interview, and takes a romantic flight, with Superman, and is still flustered. As he picks her up for their date, Clark almost reveals his true identity to her, but thinks better of it, and keeps up the facade. Nothing about dating is talked about between them again.

In the third film, Clark goes back to Smallville and strikes up a friendship with Lana Lang again. This friendship smacks of the romantic, in spite of what he learned about such things in the last film.

In the fourth film, Clark finds himself the object of the affections of Lacy Warfield, the daughter of the Daily Planet’s new editor, and humors her with a date. Shortly after, he reveals his identity to Lois again, jogging her memory of their time together, before he once again erases her memory with a kiss.

2. Jason White - In Superman Returns, which follows up a similar version of events to the first two films while ignoring the third and fourth, Superman returns to Earth after a long absence to find a Lois who is resentful of him, is now engaged, and has a five-year-old son with her fiance. After having another interview, and another romantic flight, her anger mellows. It is later revealed (presumably surprising even Lois) that her son, Jason, is actually Superman’s son (presumably from their time together during Superman 2). While Superman is in a coma near the end of the film, Lois whispers the truth in his ear before giving him a light kiss. At the end, after he awakens, Lois is still with her fiance, but the future remains ambiguous.

Lois & Clark: The New Adventures of Superman
Clark and Lois eventually dated, fell in love, andwere married and spent the rest of the series as a married couple.
 * 1)  Clark Kent / Superman  - Clark claims to have loved Lois from the first time he saw her. For her, the attraction took longer to build, but they become partners and best friends.  At the end of the first season, she is preparing to marry Lex Luthor. To stop her from marrying who he knows to be evil, Clark confesses his feelings for her. She does not reciprocate, but as the wedding approaches, finds herself fantasizing about marrying Clark instead. She is about to call the wedding off when police arrive to arrest Lex. Later, she seems about ready to tell Clark of how she feels, when he tells her, lying, that he did not mean what he said, and that he would have told her anything to stop her from marrying Luthor.Clark eventually asked Lois out on a date, and she accepted At the end of it, they shared a kiss. However, Lois became increasingly perturbed by the secretive Clark, who kept running off at random moments with half-baked excuses.
 * 2) Dan Scardino - Lois & Clark met Scardino while they were investigating the same individual. He and Lois took an interest in each otehr, and Lois, close to but frustrated with Clark, found herself having to choose between him a d Dan. In the end, she chose Clark.

DC Animated Universe
In this continuity, Lois dated Lex Luthor prior to Superman's arrival. However, she was, of course, unaware of his truly devious and evil nature. In spite of still not knowing the truth about his identity, Superman and Lois are shown having a picnic together and even kissing in Justice League. What exactly their Facebook relationship-status would say is unclear, but likely “It’s complicated.”
 * 1)  Clark Kent / Superman  - Clark has his more competent, less-nerdy demeanor with Lois in this version, but the two never have any real romantic tension in that way. That’s reserved for his Superman persona.

Smallville
Lois Lane first came to Smallville to investigate her cousin Chloe’s apparent death, which turned out to be faked. She first met Clark when she found him in a corn field, naked and suffering from amnesia, believing him to be struck by lightning (the actual explanation was much more complicated). At first, their relationship had no inkling of romantic tension, although Lana predicted it right away. Clark and Lois’ wedding is botched by the invasion of Darkseid in the series finale, in which he finally debuts as Superman to the public. In the epilogue, taking place seven years later, for some reason, they have still not gotten married, and are only then preparing for their wedding later in the day.
 * 1)  Arthur Curry / Aquaman  - When Arthur first visits Smallville, he rescues Lois from drowning. He then begins pursuing her, and the become something of an item. After the secret mission he set for himself is completed, he leaves town, and bids Lois farewell.
 * 2)  Oliver Queen / Green Arrow  - When Oliver first moved to Metropolis and begins acting as a vigilante, it was reporter Lois Lane who gave him the name “Green Arrow Bandit,” which others shorten to “Green Arrow,” much to her chagrin. As Oliver Queen, he and Lois began a relationship, which is complicated by his secretive lifestyle, ending in their breaking up. Later, she learns his identity as the Green Arrow and, with this out in the open, he discusses renewing their relationship, but she states that she cannot be a superhero’s girlfriend (irony).
 * 3)  Clark Kent / Superman  - Later, Clark and Lois grow closer, eventually working together at the Daily Planet. They finally form a relationship, and Clark reveals his secret to her. She remains close to Oliver, and in contact with Arthur, both  as Clark's teammates in their superhero group, with Oliver being Clark's best friend. Clark eventually proposes to Lois, and she accepts. Contrary to all other versions of the character, not only does she know his secret before he becomes Superman, she even helps him assimilate the glasses-wearing, nerdy-persona fo the new Clark Kent.

DC Films Universe

 * 1)  Clark Kent / Superman  - Lois investigates a Kryptonian ship and is injured by one of the robots working on it. She is saved by a pre-Superman Clark, who was investigating his past (and finds the details there), and who uses his heat vision to cauterize her wound. Lois later sets out to find her rescuer, eventually identifying him as Clark Kent, just before he debuts as Superman. Hence, like in Smallville, Lois here knows his true identity before he even makes his debut. Just after his first adventure, they kiss and begin a relationship. Years later, the two are living together. Clark is killed by Doomsday, and his mother reveals to Lois that he was planning to propose. Lois begins wearing the engagement ring he planned to give her. With Clark now resurrected, he and Lois are happily engaged.

Arrowverse

 * 1)  Clark Kent / Superman  - Clark is shown to be in a happy, long-term relationship with an offscreen Lois. He still has to avoid the constant advances of Cat Grant whenever he sees her.