Shanks Pirates. They can be considered as the coolest pirate crew in One Piece. But the best thing is that, for me, they are the ones carrying the will of Gold Roger. They are the succesors of the Roger Pirates' spirit ....until the Straw Hats are ready to take that mantle, that is! haha
One Piece and everything related to it, is own by Toei and Eiichiro Oda
P.S Did you spot the "hidden" Jolly Roger right away?