The Straw Hat Pirates are one of the strongest crews in One Piece. The crew has been through many arduous trials and has come out on top almost every single time. The Straw Hats have a good balance, but there is a clear power dynamic within the crew.
The "Monster Trio" is made up of the crew's three strongest members: Luffy, Zoro, and Sanji. The Monster Trio is responsible for taking down the strongest three enemies in every single arc. They have been involved in various arcs, and as the story has continued, their opponents have become stronger. The biggest victories of the Monster Trio not only showcase the ever-increasing strength of Luffy, Zoro, and Sanji, but also have a huge impact on the story of One Piece.
5 Vs. New Fish-Man Pirates
After two years of intense training, the Straw Hats returned to Sabaody to set out on their new adventure. Before entering the New World, the crew had to make one last stop at Fish-Man Island. As it was the first major arc after the time skip, there was no real need for the crew to fight strong opponents. Oda's plan was to use the new villains to allow the Straw Hats to show off their newly learned techniques.
The Monster Trio fought Hody Jones, Hyozou, and Wadatsumi, who were members of the New Fish-Man Pirates. The three were more powerful than ordinary humans, and they had some neat abilities. However, the strength of the Monster Trio proved to be too much. The three Straw Hats easily defeated their opponents and secured an impressive victory. The victories of the Straw Hats proved to be a major confidence booster before they entered the New World, where multiple strong enemies awaited them.
4 Vs. Arlong Pirates
With Luffy taking down the notorious Don Krieg and recruiting Sanji, it seemed that the Straw Hats could finally move on with their adventure. However, they were surprised to learn that Nami had taken the ship and run away. Luffy and co. decided to follow her to Cocoyashi Village. The crew found out that Arlong and his crew had been mistreating Nami, which infuriated them.
The crew marched on to Arlong Park, where they fought Arlong and his top officers. Sanji defeated Kuroobi in an intense fight that started underwater and concluded on land. Zoro was badly wounded from his previous fight, and he went head-to-head with Hachi. Despite his injuries, Zoro overwhelmed Hachi rather easily. Luffy was enraged while fighting Arlong for what he did to Nami. Not only did Luffy defeat Arlong, but he also destroyed the entire Arlong Park.
3 Vs. Baroque Works
The Alabasta arc is important to the story, and it focuses on the adventures of the Straw Hats as they try to help Vivi reclaim her homeland from Crocodile. The Shichibukai used his influence to incite a civil war, which nearly led to the country being completely ruined. The Monster Trio had to struggle a lot in their respective fights in the arc. Luffy was defeated twice by Crocodile, so he needed to work extra hard to ensure that the third time the outcome would be different.
Zoro fought against Mr. 1, whose body was as durable as steel, and for this reason, the Straw Hat was unable to cut him. Luckily, he managed to figure out a technique that enabled him to bypass Mr. 1's devil fruit powers. Sanji tussled against Bon Clay, who kept on using his devil fruit powers to change his face to Nami's. The Baroque Work assassin took advantage of Sanji's vow to never hit a woman and dealt a lot of damage to the cook of the Straw Hats. However, Sanji managed to trick him into changing his face back to normal, which created a small window for him to land a critical hit.
2 Vs. CP9
CP9 is an elite organization that carries out top-secret missions for the World Government. Several CP9 assassins were sent to Water 7 to steal the blueprints for Pluton, but they struck gold when they found Nico Robin. This led to an epic showdown between the Straw Hats and CP9 at Enies Lobby. During the arc, the Monster Trio obviously fought the three strongest CP9 assassins. Luffy fought Lucci, Zoro fought Kaku, and Sanji fought Jabra.
Sanji's fight with Jabra was terse, as the former was just too powerful for Jabra. Zoro had to struggle a lot in his fight against Kaku, and he only managed to take down the CP9 agent after unleashing the Ashura Ichibugin. Luffy's fight with Rob Lucci was exhilarating, and there were many exciting action sequences. Eventually, Luffy defeated Lucci with a barrage of punches.
1 Vs The Beasts Pirates
The Wano Country arc is one of the longest arcs in the entire series. The build-up for this arc started many years ago, and eventually, it came to an end in 2022. In this arc, the Straw Hats fought against the Beasts Pirates, who were known to be merciless. Facing Kaido and his crew was the toughest challenge for the Straw Hat Pirates to date.
During the raid on Onigashima, Luffy went toe-to-toe with Kaido, while Zoro and Sanji fought King and Queen respectively. Zoro defeated King with the help of Enma and Sanji's newly awakened powers enabled him to make short work of Queen. After initially losing his fight, Luffy awakened his devil fruit and combined it with Advanced Conqueror's Haki to overpower Kaido. This was a massive victory for the Monster Trio, as they got the better of some of the most well-known names in the One Piece world.