Speedrunning this with Hinton's first 4 books because why not. XP
For The Outsiders, it's gotta be Dallas. I would include Steve, but he doesn't have enough screen time (page time?) for me to form an opinion.
For That Was Then, This Is Now, absolutely no one. I love them all dearly, especially Mark and M&M. (Then again, the book did help me during a dark time...)
For Rumble Fish, Motorcycle Boy and Smokey. I swear, when I first read the book, their presences made me angry (which was so silly, considering I'm...fine with them now).
Aaaand lastly, for Tex, no one really, but I did not like Mason at the start. Thank goodness he got some redemption.
(You can tell her books are my special interest www)