Yes he is. Along with Chado, Imizu, Seki, YsY, and, even if he says no, himself. there's alot of others but you can say they're the ones topping alot of people on there personal artist faves
It's all about taste. I like Dei Shirou's smackdown doujin, but not my fav. YsY too, I don't really enjoy his art. But YsY's chibi is awesome, I must say.