3rd… hell… 5th Stringers are my bread and butter. The reason I love them so much is because they’re nobodies creators have more of a chance to make those characters grow. Wolverine, no matter how much shit you do to him, is an A list character. He will always revert back to a dude with adamantium claws and a healing factor who is on 20 teams at once. But, the Irredeemable Ant-Man? He’s gonna show up in some books here and there, and then he’ll die and then… that’s it. He’s still dead as far as I’m aware. Most A list characters can’t stay dead longer than a week.
So, yeah, I guess I like them because there’s just more freedom. They’re blank slates and nobody is gonna care what happens to them or their continuity.
Some of my personal faves (many who grew up to be A list because of persistent writers):
Dazzler, Squirrel Girl, Renee Montoya, Jubilee, the Agents of Atlas, Stephanie Brown, Shining Knight, Amethyst, Irredeemable Ant-Man. Any “young adult” character like Runaways, Firestar, Speedball, etc.
Just to name a few.