Top 10 best action anime to watch of all time

1

Katanagatari (2007)

Trailer Anime

Katanagatari is the story of Yasuri Shichika, a swordsman who fights without a sword, and Togame, an ambitious young strategist who seeks to collect 12 legendary swords for the shogunate. Shichika is the son of an exiled war hero and the seventh head of the Kyotouryuu fighting school who lives on the isolated island of Fushou with his older sister Nanami. Togame seeks him out because his bare-knuckle fighting style means he won't be ruined by the power of the sword. Togame, who has been betrayed before, convinces Shichika to accompany her on a quest to find the legendary swords. Together they embark on a journey through Edo-period Japan to collect swords used by formidable opponents.

2

Full Metal Alchemist: Brotherhood (2009)

Trailer Anime

Full Metal Alchemist: Brotherhood revolves around brothers Edward and Alphonse Elric who were raised by their mother Trisha Elric in the remote village of Resembool in the country of Amestris. Their father is Hohenheim, a famous alchemist who abandoned his family when the boys were still young, and while being cared for by Trisha, they begin to show interest in alchemy and become curious about its secrets. However, when Trisha dies of a serious illness, they are cared for by their best friend Winry Rockbell and her grandmother Pinako. 

The boys traveled the world to advance their alchemy training under the guidance of Izumi Curtis. Upon returning home, the two decide to try to bring their mother back to life using alchemy. However, the conversion of people is a taboo. During the failed transformation, Al's body is completely deformed, and Ed loses his left leg. In a last-ditch effort to keep his brother alive, Ed sacrificed his right arm to bring Al's soul back. 

3

Code Geass: Lelouch of the Rebellion (2006-2012)

Trailer Anime

Code Geass: Lelouch of the Rebellion is about Lelouch vi Britannia, who is a Britannian prince in exile, son of Emperor Charles zi Britannia and royal consort Marianne vi Britannia. Lelouch has a younger sister named Nunnally vi Britannia. Marianne was brutally murdered in the palace and Nunnally, who witnessed their mother's murder, was so badly traumatized, she lost both her sight and the ability to walk. Lelouch is furious with his father, believing that his father has made a mother and that his sister failed to turn a blind eye to their mother's death and fail to pursue their mother's killer.

Lelouch and Nunnally are sent to Japan as political pawns to hypnotize the Japanese government into a false sense of security. After the brothers are sent to Japan, Japan is attacked and defeated by Britannia. With the backdrop of Japanese ruins, Lelouch vows to his Japanese friend Suzaku Kururugi that he will one day wipe out Britannia as an act of revenge on his father.

4

Gurruen Lagann (2007)

Trailer Anime

Gurruen Lagann (The Drill of Destruction) is set in a fantasy future where Earth is ruled by the Spiral King, Lordgenome, who forces humanity to live in isolated underground villages. The plot focuses on two teenagers, Simon and Kamina, who live in an underground village and wish to get to the surface. Using a mechanic known as Lagann, Simon and Kamina reach the surface and begin fighting alongside the others against Lordgenome's forces before fighting their true enemy forces.

5

Needless (2009)

Trailer Anime

Needless is set in the year 2130 (the start date is still unclear), 50 years after World War III. The war left behind a crater where Tokyo once stood, a place now full of contaminated rubble. This point is called the "Black Point", there is no electricity (except for the Simeon building) and is seen as a spherical patch of darkness from outer space and is one of many Black Points throughout Japan. The Black Spot eventually becomes home to outcasts, some of them,  Due to pollution, various powers are acquired that are called "fragments". People who own such fragments are called "Unnecessary".