Hester

In my opinion, Hester is not the guiltiest sinner. Your answer would depend upon how you define sin. If you follow Mosaic Law, the novel's three main characters are all guilty of sin. Hester and Dimmesdale share the sin of adultery. Chillingworth would carry a multitude of sins on his heart. Thus, Hester's sin is no different or worse than anyone eles's.