There are a handful of romantic relationships in comics that are absolutely iconic. Moments like the wedding between Spider-Man and Mary Jane or scenes of flirtation between Batman and Catwoman are some of the most famous parts of the genre.
Of course, comics have always been subversive, and a number of the romantic relationships in DC & Marvel reflect this. While there are plenty of examples of relationships being poorly handled for one reason or another, many of the best and most memorable relationships are healthy yet still transgressive.
10 Swamp Thing & Abby Arcane (DC)
After her marriage deteriorated, Abby Arcane ended up in a relationship with Alec Holland, the Swamp Thing. While Alec always assumed he was a human who had been turned into a swamp monster, it was eventually revealed that the original human Alec Holland had died and imparted his consciousness to a totally different entity, a plant elemental, thus creating the Swamp Thing.
While relationships between humans and other species is fairly common in comics, this was one of the first times that such a dynamic was explicitly addressed. Abby was even arrested and taken to court for her sex life with the Swamp Thing violating US indecency laws. Despite this, they are deeply in love and would do anything for one another.
9 Wiccan & Hulkling (Marvel)
To be clear, Wiccan and Hulkling are not the first same-sex couple Marvel has had. However, most of these relationships were either queer-coded or (if they were explicit) in more adult titles like the MAX comics line. At the time Wiccan and Hulkling were introduced, same-sex relationships were considered controversial & divisive, and a common conservative talking point was to claim children could somehow be corrupted by the influence of normalizing same-sex romance.
To see two young people in a loving committed same-sex relationship with support from their parents was profoundly groundbreaking for a mainstream Marvel comic. They remain together still, and are one of the sweetest, healthiest relationships Marvel has.
8 Wolverine & Jean Grey & Scott Summers & Emma Frost (Marvel)
For a very long time, Scott Summers and Jean Grey were among Marvel's most iconic couples. Then things became more complicated, and their relationship began to struggle, especially in the aftermath of the Dark Phoenix Saga and Scott's marriage to another woman, Madelyne Pryor. Things were further deteriorated between them due to Jean flirting with Wolverine and Scott having an affair with Emma Frost in New X-Men. But finally, all of this drama has been resolved in a healthy, consenting, nurturing way.
Right now, Jean, Scott, and Wolverine are a throuple, with Scott also apparently in a relationship with Emma Frost. It also looks like Emma and Jean may have romantic attachments to one another, or at least are very close as metamours. Much of this has been shown in the art of recent X-Men stories without dialogue provided. The four are currently Marvel's most visible and healthy polycule.
7 Lisa & Ally (Sunstone by Image Comics)
While the trappings of BDSM have frequently been a feature of comics, mostly it was either a topic hinted at or used as costume inspirations (such as with the Hellfire Club). The few explicit references tended to vilify kink and kinksters, or turn non-vanilla sexual practices into jokes to be laughed at.
The Image series Sunstone written and drawn by Stjepan Sejic is entirely dedicated to a healthy, committed BDSM relationship between two women, Lisa Williams and Ally Carter. They met online, and after establishing chemistry, boundaries, and expectations, they explored kink together, engaging in a total power exchange. This is a relationship where they can laugh at one another, enjoy small intimate moments together, share in the other's interests, and still don latex and leather for a fun time.
6 Harley & Ivy (DC)
Harley Quinn and Poison Ivy are now a mainstay of the DC Universe. Their relationship was merely hinted at for a very long time, with the seeds of their dynamic planted in Batman: The Animated Series. However, before dating Ivy, Harley spent years being seen in the context of her relationship with Joker.
As she was able to grow, she recognized Joker was abusive, and also realized Ivy's feelings for her were much more than Platonic. Each of them helps to balance out the other, and to heal from their respective trauma. Despite being quite different, they are one of DC's power couples.
5 Sam Wilson & Jane Foster
There are a number of reasons why the relationship between Sam Wilson and Jane Foster was controversial. At the time, Sam had recently replaced Steve Rogers as Captain America while Jane had taken the name "Thor" and was wielding Mjolnir. Unfortunately, certain aspects of comics fandom reacted poorly and the internet erupted in a backlash against a Black man being Captain America and a woman being Thor. To be fair, some fans expressed a good-faith criticism that making "Thor" a superhero title rather than a personal name contradicted the established lore surrounding Thor.
Each of these characters also had other romantic attachments prior to their relationship. But when Jane Foster was undergoing chemotherapy, Sam Wilson stood by her. They were great in and out of costume. Their passion was thunderous, but they were at the best sharing quiet moments together.
4 The Clarke's Crew (Letter 44 from Oni Press)
Charles Soule, Alberto Jimenez Alburquerque, and Guy Major collaborated on Letter 44, a contemporary sci-fi comic about first contact in which a new President learns on his first day in office that aliens are coming. A crew of scientists and military personnel pilot a ship, the Clarke, to establish reconnaissance.
The Clarke's crew have established their own set of rules out beyond Earth. While they defer to military personnel in combat scenarios, they otherwise have a truly democratic process where even the captain surrenders her authority to establish a non-hierarchical community. They also are romantically and sexually involved with one another, sharing responsibilities and decision-making. Problems eventually arise, but not for lack of trying.
3 Marko & Alana (Saga by Image)
Brian Vaughan and Fiona Staples created Saga, a story about two lovers from different warring alien species trying to raise a child while on the run from both of their respective cultures.
Alana is a former prison guard from the scientifically-oriented planet Landfall who gives birth to her daughter Hazel in the opening scene. Her husband Marko used to be a prisoner in her care and is from the magically-based moon of Wreath. Despite being in a war-torn galaxy, they care for their daughter Hazel, have a healthy sex life, genuinely love one another, and push each other to grow. Another relationship in the comic worth noting is the one between the characters Petrichor and Prince Robot IV, who both have serious trauma and emotional baggage, but try to overcome these obstacles.
2 Batman & Catwoman (DC)
For a long time, Catwoman was portrayed as a sexy femme fatale who flirted with Batman. But the longer their dynamic lasted, the more their relationship grew until it became something serious. Batman revealed his secret identity to her during the story Hush and proposed to her during Tom King's Batman run.
Batman's entire identity is about his war on crime, which he began after his parents were murdered. During King's run, he tried to figure out what it meant to be happy. And he genuinely tried to have a relationship with Catwoman – a criminal – even as he defined himself through his crusade against criminality.
1 Superman & Lois Lane (DC)
Lois Lane was introduced alongside Superman in Action Comics #1, and the two even had their first date together in their debut issue. Right from the beginning, they were a study in contrasts. Beyond the interspecies nature of their romance (which they found easy to overcome), the two are ideological opposites.
As was pointed out while on a double date in issue #37 of Tom King's Batman, Superman's identity is the world's greatest secret (or it was at the time), while Lois is among the world's greatest reporters, dedicated to revealing secrets. She is also very much a modern woman of the city, and he is a country boy from Kansas. Opposites attract, and they make it work in a surprisingly wholesome way.