Don't know if this has been ask but what your favorite chapter cover (this is exculding mini-stories) in OP. Seeing how there more then 300 chapters and counting. There plenty to choose from.
Mine:
Luffy surfing a tide with the Merry Go in the distance.
A bit of a relaxed piece with the group louging around and the caption reading something getting funky (with Ussop holding out a sign reading "Don't Funk" XD )
A wanted poster art that featured Luffy, Nami, and Zoro posing
Another with the group running across a beach with a creature in the background (this was also used in the "Believe" opening)
The "Mugiwara Pirates" sitting on a counch (or standing in Chopper's case) with a giraffe in behind them.
and of course the recent Mugiwara Pirates vs. Cipher Pol 9 colorspread.