Major Mapleleaf from Alpha Flight, as befits a super-Mountie.
Captain America. Pretty much anyone can (and do, on many occasions) soliloquize about how much everyone adores the shit out of Cap, and never feel like they're laying it on too thick or being out of character; which is something that can't be done to many other characters without it tasting of a Creator's Pet. In the Marvel Cinematic Universe, being a Nice Guy is actually the only reason the Super Serum even worked - When it was given to a megalomaniac, it created the Red Skull. Colonel BadassChester Phillips wanted to give it to a "Strong, Fast, Obedient Soldier", and sixty years later we get to see the results of THAT. Only a Good Man could become Captain America.
Klara Prast of the Runaways. She's perhaps the only member of the team with absolutely no Deadpan Snarker traits, and is usually far less inclined towards violence than her teammates. Of course, as an immigrant from the early 1900s who was brought into the present, she can sometimes be an Innocent Bigot. Also, God help anyone who threatens her — her plant friends can get very protective...
Even more so in the Ultimate universe, where he's one of the few unambiguously good characters and fights crime purely because it's the right thing to do.
The Incredible Hulk: Bruce Banner is a kind-hearted, well-intentioned, self-sacrificing person as long as you don't piss him off. The Hulk can also be considered one although he leans more towards a Gentle Giant and a Bruiser with a Soft Center.
From X-Men there's Trevor Hawkins, also known as Eye-Boy. In X-Factor (2020) his teammate Daken is surprised that Eye-Boy's kind and friendly nature really isn't an act -– Polaris points out that Trevor had a normal and happy childhood, unlike many other X-Men characters.
