Just my opinion. I've followed One Piece over a long time (~10 years) and it was one of the first Anime I picked up.
I voted to close this question because it was too broad. I'll post my inital comment and then some alternative questions that I feel can be answered much better. This was my comment.
The question is answerable but not of great quality because the answer will ALWAYS be primarily opinion based even if it tries to use canonical measurements. Luffy a 100M bounty defeats someone which the author states is worth 500m. Sogeking has less bounty than Franky but God Ussop has twice as much? There are simply too many variables to sort out a completely Non-opinion based list of power. Compare it to the strength order of Avengers or Justice League if you will. Drawing on the parallels, Who is stronger Cap or Iron Man? Martian Manhunter or Superman? and so on...
This covers the gist of my problems.
Since there is no absolute power rating like in DBZ. Someone dropped in Dourikis and Bounties, which are very flawed.
Other than Fukurou we do not know anyone who can measure Douriki and absolute value is known ONLY for the CP9, thus making it unsuitable for anyone else. If the strength order of CP9, we have a question we can answer with the help of Douriki system!
Bounty is known to be flawed within the OP world itself. Robin had a bounty higher then Sanji, Chopper has the lowest Bounty in the crew, Ussop's recent bounty is higher then all the others except Luffy and Zoro. If the power is equivalent to bounty then this question can be answered by a simple Wikia link.
One Piece is meant to show that people are different, unique and can be weak and strong at the same time. Luffy was stronger then Enel just because of their DFs. Ussop is the only one that could beat Sugar, who could probably take every other "strong" Straw Hat. Oda regularly puts out statements about different attributes of Straw Hats. So I think questions like "What is the order of intelligence/Raw strength/Skill with Haki for straw hats?" can be answered better but would still draw opionated answer to some extent.
Another thing that comes from this is some people are right for the fight. How prepared are you for a fight, have you fought before, are you at a advantage/disadvantage due to your fighting style etc. pull a LOT of variables to consider to bring which can't all be resolved. The power of straw hats varies depending on who they are fighting and what they are fighting for (This has actually been said by Nami in the anime IIRC the Water 7 saga).
Thus according to me there are no in-universe solutions available that can answer this question completely.
I'll like to try another analogy here (Super Heroes may not have been that relatable). Which are Ash's strongest 6 pokemon? Or even which are the strongest Legendaries? Even with BSTs we all understand that one pokemon can be strong against something and weak against something else... So We can group them by BSTs but can't absolutely define a list for them.
