The more I think about it, the worst this list is. I don't think Greg Land's art is influential at all, for example. He's just controversial after he was given the nick name "O face" due to his practice of using porn to draw from. And he hasn't been around long enough to have made an impact.
Miller's work on Wolverine, Daredevil, Batman, The Dark Knight Returns and Sin City as well as 300 proves to me he's had a far more impressive impact on the industry that a guy like Land, good or bad.
and I am not a Miller fan but his influence changed the landscape of comics to this day. This is true of his art and not just his writing. Not knocking his writing influence as that was just as important. Miller is the master dealing with the look and feel of the harsh and grim neo-realism(if thats the right term) of comics. His work with Batman is a good example. Great with Bruce but completely misses the mark on Superman.