As one of the Yonko, Big Mom is one of the four most powerful pirates in the world. As the only female member, this effectively makes Big Mom the single most powerful female pirate in the world. Through her strength as one of the most powerful pirates, Big Mom has managed to amass a very powerful crew. She also possesses considerable influence within the Underworld.
Big Mom is the youngest person known to have captained a pirate crew, having led the Big Mom Pirates since she was 6 years old. Her bounty should be around 3,500,000,000 Berries.
Kaido of the Beasts, also known as the “Strongest Creature in the World”, is the captain of the Beasts Pirates and one of the Yonko.
He attempted to take Whitebeard’s life, something few would dare, and subsequently clashed with Shanks. When Gekko Moriah was in his prime, Kaido fought him and emerged victorious, having killed his entire crew.
Kaido has many underlings and other pirates allied with him and is able to claim self-governing islands as his own territories. With Caesar and Doflamingo as his associates, Kaido has created an army of over 500 Artificial Zoan-type Devil Fruit users, his Gifters. His bounty should be around 4,500,000,000 Berries.
Marshall D. Teach, also known as Blackbeard, is the admiral of the Blackbeard Pirates and a member of the Yonko. He is also the only person in history known to have the powers of two Devil Fruits, infact he possesses the strongest Logia-type Devil Fruit(Yami Yami no Mi) and the strongest Paramecia-type Devil Fruit (Gura Gura no Mi).
The most prominent feats of Teach’s power was defeating three commanders of the Whitebeard Pirates: Portgas D. Ace, Thatch, and later during the Payback War, Marco, the new Captain of the Whitebeard Pirates. After the time-skip, he and his crew fought against the Revolutionary Army and destroyed their base. It is also stated that they briefly fought against CP-0. His bounty should around 5,000,000,000 Berries.
Shanks is the captain of the Red Hair Pirates and a member of the Yonko that rule over the New World. He is also a former member of the legendary Roger Pirates, the only group to successfully conquer the Grand Line. As a former member of the Roger Pirates Crew he may know the location of Raftel, this information is enough to make the World Government terrified of him. His bounty should be around 7,500,000,000 Berries.
Whitebeard was the captain of the Whitebeard Pirates and was known as “The Strongest Man in the World” and “The Man closest to One Piece” after Gol D. Roger’s death.
In his prime, Whitebeard was one of the most powerful pirates of his generation and was one of the only men in the world who could match the late Pirate King, Gol D. Roger, in a fight (the only other known to match him was Marine Vice Admiral Monkey D. Garp, said to have cornered Gol D. Roger numerous times).
Whitebeard was the captain of the Whitebeard Pirates, directly controlling an enormous pirate fleet of 1,600 pirates divided into 16 divisions, each one being led by an incredibly powerful division commander. A testament to his power is the fact that the Shichibukai and World Government used virtually all their power to prepare to fight him. I think his bounty was over 7,500,000,000 Berries.
#2-MONKEY D. DRAGON
Monkey D. Dragon is the infamous leader of the Revolutionary Army. He is the World Government’s greatest enemy, and is the most dangerous and most wanted man in the world.
Dragon is already a powerful threat in his own right, as well as having powerful subordinates such as Sabo, Ivankov, Bartholomew Kuma, and Inazuma who are in comparison, lower in rank. This only speaks volumes of his true power.
Dragon has been shown to control the air and even lightning, just whether in general. He probably has the strongest Zoan Devil Fruit in the series.
When he was mentioned at the Summit War everyone froze, just at the thought of Dragon. Everyone is scared of him. He is at least Yonko level. Maybe the strongest character of the series. His bounty should be near 10,000,000,000 Berries.
#1-GOL D. ROGER
Gol D. Roger was a legendary pirate who was known as the Pirate King, captain of the Roger Pirates, and owner of the legendary treasure known as “One Piece”.
He was famed as the man who did what no one thought possible – conquering the Grand Line and amassed a vast fortune.
Roger was hailed as the most powerful pirate of all time. His fighting power was nearly unstoppable. Examples of his strength include fighting on equal ground with Shiki, who commanded the largest pirate fleet of the time, and single-handedly defeating the armies of several countries.
Roger was also able to understand the meaning of the characters written on the Poneglyphs, as well as write in the same language. According to Rayleigh, Roger could interpret the Poneglyphs because he had the ability to “hear the voice of all things”.
He was one of two known humans in the series who possessed the ability to hear Sea Kings speaking and one of four known humans in the series who possessed the ability to hear Zunisha speaking. I think he had a bounty of 10,000,000,000 Berries at least.