He's not the best in terms of plot and story, but does excellent in the character development aspects and has a wonderful clean crisp drawing style. AG is essentially the only long running Manga I faithfully subscribe to.
This is the best gift I can give you for now, the gift without form called Memory. I have no money, I cannot buy you much with form. Even so, Memory will last Forever!
My favorite is Atsushi Ōkubo. I love his art style and he has a different style of story telling. I see plenty of character development and he takes chances in his art style ever once and a while that makes me very happy.
Yuu Watase;I just love alot of his manga, and they are all beautiful and the plots are great. What's not to like? And after that i'd say Ken Akamatsu, for the Negima manga; great drawings, detailed plot, so many characters but all individual and distinct.