FIRST OF ALL:
DON'T start to discuss who is stronger!!!
Do you think that they will fight each other once again in some arc like it happend between
Luffy and Zoro
Luffy and Ussop
For now I can't see a reason why they have to fight each other but we can't predict what will come to us… and I don't like to see they fight each other but if it comes what fights you would like to see and for what reason???
I want to see a true fight between Sanji vs Luffy or Zoro... It would be good to see and end many speculations...
Maybe Luffy have to hurt some woman and Sanji get it wrong or Luffy will be pissed of something that isn't true like it happend in Whiskey Peak...
And for Zoro... They fight for no reason as well... Maybe a tournament