Joe Quesada

Editor-in-Chief at Marvel Comics between 2000-2011, and a very polarising figure indeed. Started off as an artist, probably best known for his work on Daredevil. He took the editor job in 2000 and, while comic sales rose since he took over, they are still a shadow of the sales in the Silver Age through the 1980s.

Currently^[when?] holds the position of Marvel's Chief Creative Officer, tasked to "ensure that all portrayals of Marvel's characters and stories remain true to the essence of Marvel history."

Some of his editorial decisions:

Spider-Man's One More Day, which attempts to make Peter Parker Younger and Hipper by dissolving his marriage to Mary Jane Watson.
Jean Grey coming Back from the Dead was also "corrected" by having her killed off, despite her massive Character Development since then.
He evidently preferred Emma Frost being altered to more of a Heel Face Turn and Spoiled Brat than even when she was a villain. So he "rewarded" Emma by sticking her into Jean's place, including being Scott Summers's Love Interest, which started with them kissing over Jean's grave.
He and Brian Bendis had The Wasp killed off, again claiming that her now widowed husband, Hank Pym, is now "more interesting" without her.
Forced Wolverine and Nick Fury to drop their iconic cigars, which they'd had for roughly 30 and 40 years respectively. Killing, maiming and making deals with Satan stand-ins is okay otherwise. Smoking doesn't even harm Wolverine, due to his Healing Factor. When he temporarily lost it, he had to quit.
Censoring Trade Paperbacks.
He likes big, big, BIG crossover events.