Shonen is the most popular anime genre because it is generally aimed towards teenage boys and young adults. That means that most Shonen series feature a good amount of fighting. At one point in time, the anime world was dominated by One Piece, Naruto and Bleach – otherwise known as "The Big Three." These three Shonen became massive hits because of their action scenes, and several of those scenes set the bar a bit too high thanks to their stellar animation and effects.
"The Big Three" all center around young male protagonists, but they have very different power systems. Naruto deals with ninja who fight with illusions and elemental style attacks, while One Piece deals with pirates and Marines who use Devil Fruits and Haki. Bleach on the other hand primarily focuses on battles between different types of spirits and special humans.
10 Luffy Vs. Rob Lucci (One Piece)
Luffy wanted to save Robin from the World Government, but in order to do that, he needed to beat Rob Lucci. This CP9 agent was a highly skilled assassin, and he ate a Devil Fruit which allowed him to become a strong leopard-human hybrid.
Their battle aired in 2007, and it still looks impressive even by today's standards. At certain points, it feels as though the audience is watching a Dragon Ball Z fight because there is a lot of fast melee combat. Luffy beats Lucci with an emotional barrage of high-speed Gear 2nd enhanced punches.
9 Ichigo Vs. Byakuya (Bleach)
When Byakuta came to bring Rukia back to the Soul Society, it was clear that he and Ichigo were going to fight. They fought on Sokyokyu Hill, and after a brief exchange, Byakuya releases his Bankai. When Ichigo sees its power, he uses his Bankai for the first time.
Byakuya can control thousands of small blades, yet Ichigo is able to fight back thanks to his Bankai's speed. Ichigo nearly dies when Byakuya uses his Bankai's true form, but he is saved by his inner Hollow, and he proceeds to battle with his Hollow form for the first time. This battle originally aired in 2005, and it set the bar for Bleach's future fights.
8 Zoro Vs. King (One Piece)
Each member of the Straw Hat Pirates fought during the Onigashima Raid, and Zoro eventually fought a one-on-one battle with King – Kaido's right-hand man. King was a Lunarian, which means that he had a pair of large wings. His body could produce flames as well.
Zoro is able to fight him on pretty even terms, and as the battle continues, he uses advanced Conqueror's Haki for the first time. Their battle ends in Episode 1,062, and the animation of their final clash is beautiful and epic. King's attack looks like a flaming red dragon, while Zoro looks like a green demon.
7 Madara Vs. Allied Shinobi Forces (Naruto)
There was a lot of fighting during Naruto's Fourth Great Ninja War, and things were pretty even, but that all changed when Madara Uchiha entered the fray. Episode 322 of Naruto: Shippuden saw a reanimated Madara fighting the entire Fourth Division of the Allied Shinobi Forces.
Madara charges straight into the division and decimates dozens of ninjas with taijutsu, and he proceeds to unleash devastating Fire Release ninjutsu. When he uses his Susanoo, he takes out multiple ninja with each attack. The battle ends with Madara using the Rinnegan to summon a pair of meteors down from space.
6 Ichigo Vs. Ulquiorra (Bleach)
Ulquiorra overwhelmed Ichigo for the majority of their fight, and when he used Resurreccion: Segunda Etapa, he completely dominated Ichigo. It ended with Ulquiorra blasting a hole through Ichigo's chest. Orihime cried and begged for Ichigo to help her, and he was somehow able to hear her. He vowed to save her, and in doing so, he transformed into a Hollow.
While in this form, Ichigo had the power of a Vasto Lorde, and he was able to overpower Ulquiorra. They exchanged powerful Ceros, and Ichigo was able to cut through Ulquiorra's body like butter. This was arguably the best animated fight in the original Bleach anime.
5 Naruto Vs. Pain (Naruto)
Pain was arguably the Akatsuki's strongest member, and he killed Jiraiya and Kakashi. He also destroyed the Leaf Village, which means that his fight with Naruto was very personal. The battle starts with Naruto destroying one of Pain's bodies, and he slowly eliminates four more bodies until the Deva Path remains.
This was the first time Naruto used Sage Mode in battle, and Pain got to deliver his famous speech about the cycle of hatred. When Pain stabs Hinata in front of Naruto, he unleashes the power of the Nine-Tails and fights with six tails. The fight ends with Naruto driving a Rasengan into Pain's gut, and to this day, it is one of Naruto's most iconic moments.
4 Worst Generation Vs. Big Mom & Kaido (One Piece)
At some point during the Onigashima Raid, Luffy makes it to the rooftop to face both Big Mom and Kaido. He is joined by Zoro, Killer, Eustass Kid, and Trafalgar D. Water Law. The ensuing battle includes some of the best animation that One Piece and anime fans have ever seen.
Every member of the Straw Hat alliance gets a chance to shine by hitting Kaido with a devastating attack. Kaido and Big Mom retaliate, with Big Mom producing a lightning storm that was as powerful as a natural disaster. This battle will always stand out because it featured many of One Piece's strongest characters going all out.
3 Naruto Vs. Sasuke Final Battle (Naruto)
Naruto and Sasuke fought each other several times, but it is their final fight that really stands out. The fight was so monumental that it was given a 1-hour special, and the quality of the animation was similar to what is usually seen in high-budget anime films.
The battle featured some of the series' best taijutsu and ninjutsu moments. At one point, it was a battle between Naruto's Nine-Tails Chakra Mode and Sasuke's perfect Susanoo. There were several jutsu clashes, and each one was more significant than the last. This fight is a true testament to friendship, as Naruto was willing to die in order to save Sasuke from a life of hatred.
2 Yamamoto Vs. Yhwach (Bleach)
Bleach: The Thousand-Year Blood War has been a huge success thus far, and it features high quality animation that was not seen in the original Bleach anime. The most important fight of the first season saw Captain Commander Yamamoto take on Yhwach – the Quincy King.
The fight begins with a fluid exchange, and when Yhwach draws his sword, Yamamoto releases his Bankai for the first time. The fire that engulfs Yamamoto's body looks spectacular, and the Quincy abilities that Yhwach uses are equally impressive. Yamamoto's sword can summon the dead and annihilate anything with a single tap, and both these effects are very well done.
1 Luffy Vs. Kaido (One Piece)
One Piece fans waited more than a year to see Luffy's Gear 5 transformation in the anime, and for the most part, they were not left disappointed. Gear 5 is considered the most ridiculous power in the series, and the animators captured its ridiculousness by giving the first part of the fight goofy Looney Tunes-style animation and sound effects.
This sounds like a silly choice, but it works very well given Luffy's personality and love of freedom. He literally handles Kaido's massive dragon body like a wet noodle. The second half of the fight is more tame, and it features more Haki enhanced exchanges. The final shot of Luffy's colossal fist slamming into Kaido's flaming body is especially impactful.