I've been reading Kevin Rau's H.E.R.O. series...they're fun. A friend mentioned the Jack Blank series (Accidental Hero, and a few others)...but, I haven't tried them out yet.
I loved Mercedes Lackey's fantasy novels, but, for some reason, had a hard time getting into her superhero fiction. I stopped about half way through the first book. I purchased the series...and am going to take another shot at them. I love her work, so, I think I wasn't in the correct mind frame (unemployment, etc., in RL) to give it a true shot.
There's a self published/small press publisher author who writes an Axiom-man series...a new Canadian super hero who has powers but they're not over the top...so he has quite a few limitations. They're good reads and fast reads as well.
Peter Cline's Ex-Heroes is good too...a bit different being that they're novels based on zombies and superheroes. I've only read the first in this series, but planning on reading the others.
There have been a lot of new meta fiction/superhero fiction writers coming out in the last few years. I have fun looking through the "Reader's also Liked" threads in Amazon to get new ideas.