I'll name 2 comicbook films and what I feel are underrated aspects of them.
Chris Reeves Superman characterization in Superman 1 and 2.
Now, for a performance and that has been praised for decades, to see Chris Reeves Superman and underrated in the same sentence.
However, I feel that alot of times when Reeves's Superman is discussed and idolized, much of he times, fandom tends to forget how nuanced and three dimensional a characterization it is.
His Kal El/Clark/Superman, was not the stolid boy scout that Superman is often perceived to be.
His Clark was a guy who , while being fundamentally good, was conflicted about his role as Superman in relation to his personal life.
He could be "selfish" in the sense that he was willing to turn back time and give up his life as Superman to have a life with Lois Lane, without taking into account the consequences of his actions.
He clashed with his Father and his beliefs , especially in Superman 2 the Donner cut.
He did make mistakes based on his emotions without taking into account the long term consequences and effects of his actions.
He was a passionate and emotional guy. He wasn't perfect, and he certainly wasn't a stolid , humorless, and emotionless guy, who never made mistakes .
As much as you hear the refrain "Superman is not relatable", Chris Reeve's Superman was as close to being a Human being as any portrayal of the character before or since , Imo.
He had a sense of humor. He flirted with Lois Lane. He was a caring person. He loved his family, yet at the same time, had to go through what we all go through in having to make your own choices about your future, even if that may conflict with your families wishes.
The writers , directors, and the actor, portrayed him as Human being as opposed to as a god.
I think one of the reasons why the other film versions of Superman have faltered ,and a reason why alot of screenwriters have such a difficult time with writing Superman films, is because they approach the character as a god , as opposed to as a Man .
Donner and Co focused on the Man aspect of Superman , and as such, gave us a three dimensional characterization and performance that has endured and has set the benchmark for the character.