Frank Miller has been a profoundly influential man in the comics world. In the 80s his take on Batman and Daredevil were landmarks. And his original work, like Sin City, also carved out new territory.
Miller had a huge role in pushing comics in its current grim and gritty incarnation.
In recent years, with the movies 300 and Sin City, Frank Miller's influence has spread to mainstream film. Actually the Batman movies, from Burton to Nolan, all owe a huge debt to Miller's work in the 80s.
An impressive man.