The Straw Hats are like a family, and they have stuck with each other through thick and thin. Initially, it was just Luffy, but, as he has continued to travel, he's gained more and more comrades. Sanji joined the crew during the Baratie arc and from the very first moment that Luffy met him, the latter wanted Sanji to join the crew.
Sanji is not just the cook of the crew, but also a part of the Monster Trio. Unlike Zoro and Luffy, Sanji is actually quite bright and capable of making the right decisions, and he is undoubtedly one of the smartest characters in One Piece. Aside from Luffy, Sanji has saved the crew on the most occasions and some of these moments have been forever etched into the memories of One Piece fans.
7 Opened The Gates Of Justice
The Straw Hats faced an uphill battle when they were fighting against CP9 and the Marines at Enies Lobby. When Luffy finally defeated Rob Lucci, the Straw Hats were getting ready to leave Enies Lobby as the Marines had a lot of backup and the Straw Hats were too tired to fight them.
Luckily for the Straw Hats, Sanji had used his intelligence once again. This time, he had pulled the lever of the switch that closed the Gates of Justice, which allowed the Straw Hats to escape the Marines unscathed.
6 Saved The Crew By Making A Cake
Many fans believed that Whole Cake Island would focus on Sanji becoming stronger, but the arc instead covered his past and developed his character further. When Luffy was fighting against Katakuri in the Mirror World, Big Mom was on a rampage in Totto Land. Fuelled by Perospero's lies, Big Mom was heading for the Thousand Sunny to kill the Straw Hats and take back the Wedding Cake.
After Luffy safely returned from the Mirror World, Sanji got him back to the ship. As Big Mom was still chasing them, they needed to find a way to escape. With the help of Pudding and Chiffon, Sanji managed to bake a cake that was able to stop Big Mom and her rampage. Once Big Mom ate it, she was awestruck and stopped her pursuit. So, Sanji's cooking saved the crew from certain death.
5 Saved The Straw Hats From Doflamino
After the Straw Hats left for Dressrosa, they were split into two groups. Sanji's group had Caesar, and they were near Green Bit. They knew that it wouldn't be easy to defeat someone as powerful as Doflamingo, so they tried to maintain their distance.
However, Doflamingo was able to locate Sanji's group. Just as he was getting ready to kill them, Sanji appeared and stopped the Warlord. Sanji was overwhelmed by Doflamingo, but his intervention was crucial in saving the group. Also, it bought enough time for Trafalgar Law to attack Doflamingo and grab his attention.
4 Saved Usopp From Jabra
During the Enies Lobby arc, the Straw Hats faced the ginormous task of beating members of CP9. They had to beat them at any cost because it was the only way of saving Robin. In the arc, Zoro and Usopp had to fight against Kaku and Jabra.
While Zoro was able to keep Kaku at bay, Usopp clearly did not have enough strength to fight against Jabra. Just as the CP9 member was getting ready to kill Usopp though, Sanji kicked Jabra and stopped him in his tracks. They continued to fight, but it quickly ended once Sanji decided to get serious.
3 Mr Prince
The Straw Hats were trying to bring down Crocodile, who was the leader of Baroque Works. In the arc, Crocodile showed countless times why he is one of the most intelligent characters in One Piece. Crocodile was able to capture almost all the Straw Hats and Smoker.
Only Chopper and Sanji avoided being caught by Crocodile. After Crocodile and co. left the Straw Hats to die, Sanji was able to intervene at the right time and save the crew from being drowned and then being eaten by the Bananawani.
2 Saving Luffy From Drowning
Sanji does not have a devil fruit which allows him to fight even underwater. This makes him one of the biggest assets to the crew because there are many devil fruit users in the crew.
When Luffy was fighting Arlong, the former was trapped underwater, and, as Luffy is a devil fruit user, he couldn't fight there and was struggling to free himself. As a result, it fell to Sanji to free Luffy, and, after toiling for a long time, he was finally able to save his captain. This allowed Luffy to go back and fight and defeat Arlong.
1 Rescuing Usopp From Enel
Enel was the main antagonist of the Skypiea arc, and was extraordinarily powerful. Only Luffy was able to fight against him because his Gomu Gomu no Mi was a direct counter to Enel's Goro Goro no Mi. At that time, the Straw Hats had no concept of Haki, which made it even more difficult to defeat Enel.
When Enel was getting ready to kill Usopp, it seemed as though the latter's death was inevitable. However, Sanji managed to arrive in the nick of time. He kicked Usopp towards Nami and ended up tanking one of Enel's strongest attacks. Furthermore, Sanji messed with Enel's ship, which stalled the villain's plans for a little longer.