Even though she was never a writer or artist, Karen Berger is one of the most influential people in comics. She has won three Eisner Awards for Best 
Before the British Invasion of the late 1980s, Karen Berger edited a bunch of seemingly random books for DC, including horror anthology House of Mystery, fantasy maxiseries Amethyst, Princess of Gemworld, and George Perez’s mythology-influenced reboot of Wonder Woman. These series along with Alan Moore’s Swamp Thing lay some of the future groundwork for Vertigo. They were stories with well-developed female characters (Wonder Woman, Amethyst and the various princesses, Abby Holland), a plethora of literary references, spanned a variety of genres, and some of them had a beginning, middle, and end. One of the great things about Vertigo was that the creator got to choose when the series ended. Neil Gaiman chose to conclude Sandman after 75 issues before deciding to write the prequel Sandman Overture, and Brian Azzarello and Eduardo Risso finished 100 Bullets after 100 issues before reviving it. This made comics like serialized television shows or long novels and helped give them credibility among the general public and academics.The Berger-edited Sandman #19 is the only comic to win a World Fantasy Award, which it did in 1991 for Best Short Fiction. However, Berger used long running titles, like Hellblazer and Swamp Thing, to break in future comics greats like Garth Ennis, Brian Azzarello, and Brian K. Vaughan. Berger’s eye for talent, especially British writers, helped define the comics industry. I would hazard a guess that the majority of active comics creators have done at least one project for Berger.
The biggest and most famous thing that Karen Berger did in her career as a comics editor was to usher in the British Invasion where she hired British comics creators, who had mainly done work for 2000 AD or Captain Britain, to revive languishing characters or properties for DC Comics. Some of these creators, like Alan Moore and Grant Morrison, ended up writing some of the greatest superhero stories of all time, like Watchmen, The Killing Joke, All-Star Superman, and the Berger-edited Arkham Asylum. Unfettered by nostalgia, these creators turned Golden or Silver Age B-List heroes into vehicles for some of the greatest comics stories of all time, like the Berger-edited Animal Man #26 where Animal Man met the creator of his adventures, Grant Morrison. Berger provided guidance for these young, occasionally iconoclastic, imaginative creators and let them explore storytelling itself through their writing while creating timeless characters like John Constantine and Death of the Endless.
As well as helping British creators find a bigger audience, Karen Berger has also kickstarted the careers of many female comics creators, like Pia Guerra, the artist on the Eisner-winning Y: The Last Man, Rachel Pollack, who wrote Doom Patrol when Vertigo launched, and Eisner nominated Amy Reeder, the penciller and cover artist on Madame Xanadu. In fact, the first Vertigo comic issue Sandman #47 was drawn by Jill Thompson, who would later work on Black Orchid and the manga-inspired graphic novel Death: At Death’s Door. She is responsible for the cuteness that is the Li’l Endless. Berger has also recruited fantasy novelists like Caitlin Kiernan todo comics like Sandman spinoff The Dreaming.
Throughout her career, Karen Berger has opened up the world of comics to creators and fans, who are interested in something beyond capes and tights. Even though she is no longer the executive editor at Vertigo, her influence can be felt in the presence of Animal Man, Swamp Thing, and Constantine in DC’s New 52 along with some of the comics at Image, which has also become a place for talented creators to explore different genres and controversial topics through their writing. In her time at Vertigo, Berger made the imprint a place (mostly) free from censorship and filled with flawed, but memorable characters and legendary comics runs, like Neil Gaiman’s Sandman, Bill Willingham’s Fables, Garth Ennis and Steve Dillon’s Preacher, and Brian K. Vaughan and Pia Guerra’s Y: The Last Man. Karen Berger is definitely the most influential female comics creator and maybe the most important person in comics over the past thirty years.