Daredevil: In Daredevil (1998) #38, when White Tiger (Hector Ayala) was wrongfully arrested for murder, his wife Soledad intended to file for divorce immediately because Hector had promised her he'd give up being a superhero. Matt Murdock convinces her to hold off divorcing him until after the trial because if she divorced him right away that would just send the message that he's guilty. Realizing this, Soledad admits that she knows he's not guilty and still loves him, and agrees to hold off the divorce until the trial is over and support him.
Deadpool thinks Bloody Mary is too crazy for his tastes. Let that sink in for a moment — the guy who is the poster boy for Crazy Is Cool has a limit on crazy.
Also, Deadpool might be willing to kill anyone he comes across, but he won’t kill children.
General Thaddeus "Thunderbolt" Ross can come off way to obsessed with taking down The Incredible Hulk and crossing lines doing it. However, Ross is also a dedicated soldier so if it came down to the Hulk or going against America, Ross would choose the former. He's even stood up to fellow soldiers ready to betray their oaths to take down the Hulk and regrets some of his darker actions that tarnished the uniform he holds dear.
In X-Men: Days of Future Past - Doomsday, Ross is initially on board the government's efforts to take on mutants. However, when Henry Peter Gyrich and Valerie Cooper start making plans to send the army to start herding mutants into camps and use force if they don't comply, Ross surprises them by bringing up the Posse Comitatus Act of 1878, which expressly forbids the US military from enforcing any laws - like e.g., the Mutant Control Act - on American soil.
Cooper: I'd never expected you to be a mutant sympathizer.
Ross: That makes two of us, ma'am. Truth is, I never knew what I'd say if the day came when I was given an order I considered to be immoral. Now I do.
The Punisher: The Punisher has a number of standards that keep him from crossing the line from Anti-Hero to just straight up murderous villain.
He doesn't kill cops, even crooked ones. If it happens, it was usually an accident, legitimate self-defense, or a truly egregious Asshole Victim even by Frank's standards.
He'll spare people who committed crimes under duress, since if whoever was forcing their hand was gone, they wouldn't reoffend. The trick is getting him to not murder you long enough to make your case for this.
He Wouldn't Hurt a Child, under the logic that they don't fully know what they're getting into and can learn better, especially with his visit serving as a reality check.
He leaves criminals who are being processed by the justice system (i.e. in court or in custody) alone, and he won't go after people who have been legitimately exonerated by a court of law- though they're fair game if the trial was clearly rigged.
His relationships with most superheroes are strained at best, but Frank will never actually try to kill any, because he respects that they're trying to help people even if he doesn't think they're hardline enough (and he recognizes that he would stand no chance against the sort of threats the Fantastic Four and the Avengers handle). Superheroes in turn tolerate Frank because of his ironclad rule about never harming innocents.
He can recognize the lesser of two evils when he sees it; the reason the Kingpin has survived decades as New York's undisputed don is because Frank realizes that he keeps order in the underworld and his death would cause much more problems.
Frank goes out of his way to discourage people from following his path, as he realizes that he's a really bad role model.
Spider-Man: J. Jonah Jameson may be a big-time Jerkass who hates Spider-Man with a passion, but there are still some lines he won't cross:
He stands up for human rights... because he Hates Everyone Equally! Notably one DA initially had his support because of his anti-Spider-Man campaign... then he found out that the guy was not only involved in organized crime but was also a massive racist who planned to screw over black people once he was elected. Jameson promptly turns over evidence that exposes the crooked candidate. As part of this, he's also quite commonly portrayed as being in favor of mutant rights, despite his usual antagonism towards powered individuals (often justified as his ire being directed towards vigilantes and others who use their powers without oversight, not just those who are born different).
He is absolutely committed to truth in reporting. Despite his hatred of Spidey, Jameson has always refused to use fake images in his newspaper. And though he is always the first to accuse Spider-Man of crimes, he's also usually the first to retract his statement when he is proven wrong, at one point remarking that he believes that claiming Spidey to be a menace prevents him from actually becoming one.
He's also never wanted Spider-Man dead, just unmasked and imprisoned. Even when he commissioned the Spider-Slayer robots, he was nervous about the name and only accepted it when their creator (who was a genuine villain) said that it was for Rule of Cool purposes.
Despite his dislike of the superhero community (which can border on outright hatred Depending on the Writer), Jameson grew up reading Captain America comic books, and Cap is frequently portrayed as the one superhero that Jameson will not launch campaigns against.
One Punisher / Spider-Man comic has Peter call the Bugle to ask if they're interested in pictures of a Nazi preacher named Hartmann, since he doesn't want to waste film on pictures they won't buy. JJJ instantly grabs the phone and yells at him to take pictures, claiming he hates him more than Spider-Man.
We didn't fight WWII to put up with his brand of @%$# now!
X-Men: During the Fall of X storyline of X-Men: The Krakoan Age era, both Captain America and Iron Man tell various mutants that they are more than willing to let them kill members of Orchis for their actions during the third Gala and afterwards. Captain America in particular is not keen on letting fascism spread in his country again.
