My predilection for championing losers shows in my favorite superhero: Dell's Brain Boy. I've liked this character ever since his debut in the sixties. While my artist friends were doing their knock-offs of Green Lantern and The Flash I was drawing knock-offs of Brain Boy.
I don't know precisely why BB strikes a chord with me. Part of it is that he has no costume; I've always liked non-costumed heroes. Another part is that his superpowers are "believable" (in comic universe terms, that is) and seemingly based in science. I also liked the fact that he was imperfect. He made mistakes, got scared, and sometimes had to strain his powers to the limit to win the battle.