There are lots of great artists, but unfortunately I dont know any of western ones. So I'd just like my fave H-mangaka artists.
Hanaharu naruko, Inkey, Jingrock, Saitom, Meme50, Bubuzuke (great at drawings sexy lips), Takeda Hiromitsu, P-Collection, etc. There are many more, but if I list all of them, would be too overwhelming.