By this i mean the character that contributes the smallest amount to the crew, not the show. This is counting Morale, Occupation on the ship, and combat skills. For me it is
((Most Significant to least significant))
Luffy
Zoro
Nami
Sanji
Chopper
Franky
Robin
Usopp
Brook
The reason I have Nami and Chopper so high is because they play crucial roles on the ship that could mean life or death. Sanji is lower than Nami because IMO the straw hats would still survive without his cooking, they just wouldn't be eating 5 star meals every night, probably just noodles or something.
