One Punch Man
Anime Like Hunter x Hunter
First off, the obvious. One Punch Man and Hunter x Hunter are done by the same studio, Madhouse. This means at the very least the two shows have similar animation styles and themes, but the similarities go beyond that. The shows each revolve around becoming the best of something, the best hero or the best hunter. There’s even a direct similarity as One Punch Man has the Hero Association, while Hunter x Hunter has the Hunter Association. Both organizations have a ranking system, and send their respective professionals out to combat evil forces and protect humanity.
There’s plenty of crazy action to be found in both anime, and characters have specialized moves or powers. In many ways, One Punch Man feels like Hunter x Hunter with a superhero theme.