Y'all. Are RETARDS.
Blchh, Askray. The stuff that isn't loli is alright, at least. Somewhere above average. But then there's all the loli.
Aesthetically speaking, Saiki Keita, Jam Ouji, jinjin, what little Tuna Empire does, Juubaori Mashumaro, and Isago-Sou (when he's not going overboard with the bust size) would be the artists that I'd say draw the best dickgirls; I'm sure I'm forgetting one or two artists, at least, and there're others who I don't know the names of; though when it comes down to individual girls, and adding in stuff like character and plot, the arguments that could be made for "best" multiply endlessly.
But this thread is about favorites, and if I had to pick one, Yumika may well be it. (Blah, blah, not a futa, blah.)