There are a lot of amazing OP fanartists out there, but Tsuyomaru is way above anyone else. I love how there's a sense of realism to the style, and the fact that they draw a wide range of characters whether they're male, female, young or old. The colouring is done digitally, but it looks as if it's done by paint.
Here's their official site, pixiv, deviantART and selections from Zerochan.
Last edited by Asarii; September 16, 2013 at 11:29 PM.
For one Piece, I direct some fans to this guy