ETA: Please Read the Edit Before Posting
This is partly inspired by my Avengers #200 thread. One of the things I find fascinating is that there are times characters have done some screwed up things and later writers have had a chance to retcon it. Instead, they decide to have the character explicitly say there is no easy out, acknowledge their shortcomings, and try to do better. Avengers Annual 10 is one example since I recently re-read that too and I'm glad to see the characters don't blame Marcus on mind-controlling them. They just admit their failings. Which, in the context of someone who was victimized like Carol Danvers, is refreshing.
Another example is the Hank Pym/Janet thing. After the trial of Hank, they use a special device to see if maybe Hank had been mind-controlled and Hank says "no, I wasn't. This is something I have to own and try to make up for my mistakes." It's a wonderful redemption moment that, sadly, doesn't seem to stick. Likewise, there are at least two characters who had terrible actions that could have been blamed on Skrulls. The first is Tony Stark for Civil War. They hint at it in the story and I'm glad they don't go that route. Likewise, Quicksilver in Son of M. His actions were terrible. He killed a person. But he did it in the name of saving the mutant race (raising questions of whether he was becoming like his father). In the end, the official story that gets him pardoned is that it was a Skrull that did that, but I'm glad they don't make it a Skrull for real. His actions had consequences and those matter.
What do you guys think? Was it important for these events to not be rationalized away but "owned" by the characters? Can anyone think of other examples?
ETA: Just to be clear, this thread isn't just "things you want retconned." It's about things where there were clear opportunities presented to retcon something and Marvel did not go that route. Please don't just post things you wish were retconned.