While it is easy to view Marvel and DC as warring factions in a battle of comic book universes, that is far from the truth. Both companies are simply two sides of the same coin that are in more of a friendly rivalry. So much so that they share writers to provide the best stories for the fans.
There are comic book writers that are known for their long history with one company such as Marv Wolfman and his plethora of DC comics or Al Ewing with his long-running history with Hulk comics. However, there are many famous writers who have contributed to stories from both universes.
Frank Miller
Despite his more modern comics being the subjects of controversy and division amongst fans, Frank Miller is still a recognized name in the comic book world. For DC, Frank Miller reinvented Batman with his Year One story and The Dark Knight Returns, one of the most famous DC graphic novels of all time.
Miller gave a similar treatment to Marvel's Daredevil comics. He helped turn Bullseye and Kingpin into Daredevil's most sinister and iconic villains through stories such as Born Again and Devils. The now-famous black suit was a creation of Frank Miller's that even made its way into the Netflix adaptation.
Brian Michael Bendis
Another Daredevil writer, Brian Michael Bendis made waves during his tenure with Marvel. From his modern Daredevil comics to the Avengers VS X-Men storyline to being the co-creator of the next generation Spider-Man: Miles Morales who recently starred in his own video game. Fans have called Bendis one of the best Marvel writers of the modern era.
On the DC side, Bendis' work tends to be hit or miss with fans. His Superman run felt like a step backward from Peter J. Tomasi's run when Rebirth debuted. However, Bendis did manage to earn fans via his work with Legion Of Super-Heroes and Young Justice comics. Even then, Bendis was critiqued by fans, especially when he aged up Jon Kent's Superboy in a drastic way.
John Byrne
For years, John Byrne was a writer of Uncanny X-Men comics alongside Chris Claremont. They created famous stories including the Dark Phoenix Saga and Days Of Future Past. John Byrne was also responsible for reinventing the Fantastic Four, resulting in massive cosmic adventures that would shape the future of Marvel's first family.
After Crisis On Infinite Earths, John Byrne entered DC by taking over Superman and doing what he did with Fantastic Four; he created a more down to Earth and relatable Superman who dealt with more personal issues and acts as an optimist in a pessimistic world.
Jack Kirby
One of the most famous names in comic book history, Jack Kirby was responsible for the co-creation of Captain America, then worked alongside Stan Lee to bring about famous heroes such as The Hulk, Fantastic Four, X-Men, Iron Man, and even the Eternals.
With DC, Jack Kirby was the creator of the Fourth World comics. While they weren't as successful as other famous titles, Fourth World remains a significant series that expanded the lore of Apokolips and New Genesis. The New Gods including Darkseid, Steppenwolf, Big Barda, and more have become integral parts of the DC universe.
Kelly Sue DeConnick
In 2012, Carol Danvers was revitalized with a more streamlined design and story along with a new definitive codename: Captain Marvel. This was thanks to Kelly Sue DeConnick who respected and honored the many versions of Carol Danvers of the past while reinventing her for a modern age.
Other titles such as Osborn: Evil Incarcerated, Avengers: The Enemy Within, and Latverian Prometheus showcase DeConnick's talent with Marvel properties. With DC, Kelly Sue DeConnick took on the Rebirth era Aquaman, contributing to the hero's rise in popularity and showing that he is far more than the man who can talk to fish.
Scott Snyder
During the New 52 era of DC, Scott Snyder became one of the biggest names when it came to Batman comics. He was directly responsible for the creation of the Court Of Owls as well as The Batman Who Laughs, one of Batman's most evil villains. Scott Snyder also created Duke Thomas who would become The Signal.
Other works include Justice League, Superman Unchained, The Batman Who Laughs, and most recently Dark Nights: Metal. Scott Snyder's tenure with Marvel is not nearly as extensive but he did expand on the Noir universe with Iron Man Noir, creating a more steampunk version of the character.
Chris Claremont
As mentioned, Chris Claremont worked with John Byrne to create iconic X-Men comics such as Days Of Future Past and the Dark Phoenix saga but that is just scratching the surface. Claremont has continued to write X-Men stories from the 1980s even to this day including the famous story Wolverine which served as the inspiration for 2013's The Wolverine.
For DC, Claremont took on series such as JLA, Batman: Black And White, and even created his own series with Sovereign Seven. Sovereign Seven tells the story of extraterrestrial outcasts trying to blend in on Earth but end up being defenders of their new home.
Gail Simone
One of DC's most beloved writers is Gail Simone due to her instilling new life into female-led comics. Some of Gail Simone's best comics include the Birds Of Prey series, Batgirl, Wonder Woman, Secret Six, and the creation of Ryan Choi, the All-New Atom.
Though she is more famous for her DC titles, Gail Simone has dabbled in the Marvel universe. She created the female-led team known as the Hotshots, and wrote for Fantastic Four, Iron Man, and Domino's solo series.
Mark Waid
After Frank Miller, one of the most influential writers of Daredevil was Mark Waid who took on writing the comics from 2011, relaunching the character for new readers. Waid lent his writing skills to Doctor Strange, The Indestructible Hulk series, Captain America, and more.
However, his work with DC might be considered even more famous as he created the now-famous Elseworld story Kingdom Come. He worked on The Flash comics for eight years and even helped create Impulse, Barry Allen's grandson and a very powerful version of The Flash. Other titles by Mark Waid include Wonder Woman, Legion Of Super-Heroes, and Secret Origins.
Grant Morrison
From relaunching Doom Patrol to creating one of the most famous Superman stories of all time with All-Star Superman. Grant Morrison is a name often spoken about in the DC community thanks to his many contributions: the creation of Damian Wayne, Wonder Woman: Earth One, Arkham Asylum: A Serious House On Serious Earth, and more.
For Marvel, Grant Morrison rebooted Marvel's flagship franchise with New X-Men comics, bringing new life to many characters instead of focusing solely on Wolverine. Morrison took on other but more obscure titles including Marvel Knights and Miracleman, further showcasing how experimental he is as a writer.