I'm partial towards Nami. I've done a better job during my tenure at OJ debating this. Though this time I'll keep it brief.
First point is lazy but still true, she's the third Strawhat to join.
She's got more connections with people than Sanji (I'm struggling to find the right words but @TheAncientCenturion put it nicely) She's the only reason they are capable of getting anywhere.
Outside of combat, if Luffy and Zoro ain't there, she's in charge. And in the case of navigating, she sometimes managed to override Luffy. In a combat situation the mantle of leadership usually went to Sanji. If Luffy and Zoro weren't there
First point is lazy but still true, she's the third Strawhat to join.
She's got more connections with people than Sanji (I'm struggling to find the right words but @TheAncientCenturion put it nicely) She's the only reason they are capable of getting anywhere.
Outside of combat, if Luffy and Zoro ain't there, she's in charge. And in the case of navigating, she sometimes managed to override Luffy. In a combat situation the mantle of leadership usually went to Sanji. If Luffy and Zoro weren't there