As you know,
Every arc, one straw hat star is shining. And I want to learn your thoughts. My list :
Arlong Park : Zoro and Sanji
Alabasta : Mr Prince Sanji
Skypia : Sanji
Enies Loby : Sanji
Thriller Bark : Zoro
Dressrosa : Zoro
WCI : Brook
I made list based on role of the arc. Like Brook stole copy.
I would give Skypeia to Wiper, the absolute goat of the arc, he even killed Eneru. Sanji had 1 fight whole arc and it was a 3v1, yea he saved Nami from Ener but that's pretty much all he did. Is not true that we didn't see much action from SH since Zoro had 2 big wins and Chopper soloed a priest. Robin had a big 1v1 aswell and she wasn't afraid to face Ener and was the first one to get up from the lightning shock. Still, Wiper did better than everyone else and even than Luffy i would say.
I would give Ennies Lobby to Zoro. He had his fights, he had moments were he was the one to lead their forces, and was hyped by those fodders saying "how is he not the captain?". But I like the most how he looked really pissed off and eager to save Robin, which eventually managed to do (Kaku was the one with the right key). And his Ashura moment outshined everything else.
And last but not least, give WCI to Sanji ffs. Had no proper fights (althought he no diffed Luffy) but many clashes, big moments such as dodging Katakuri bullet, kicking Oven without letting anyone see him, kicking Bobbin into the wall. Plus a lot of focus from the author on his personality traits, which is something very rare in One Piece, and even a love story, which is something even more rare.