One Piece

Gol D. Roger was known as the "Pirate King," the strongest and most infamous being to have sailed the Grand Line. The capture and death of Roger by the World Government brought a change throughout the world. His last words before his death revealed the existence of the greatest treasure in the world, One Piece. It was this revelation that brought about the Grand Age of Pirates, men who dreamed of finding One Piece—which promises an unlimited amount of riches and fame—and quite possibly the pinnacle of glory and the title of the Pirate King.
Enter Monkey D. Luffy, a 17-year-old boy who defies your standard definition of a pirate. Rather than the popular persona of a wicked, hardened, toothless pirate ransacking villages for fun, Luffy’s reason for being a pirate is one of pure wonder: the thought of an exciting adventure that leads him to intriguing people and ultimately, the promised treasure. Following in the footsteps of his childhood hero, Luffy and his crew travel across the Grand Line, experiencing crazy adventures, unveiling dark mysteries and battling strong enemies, all in order to reach the most coveted of all fortunes—One Piece.
[Written by MAL Rewrite]

One Piece Movie 9: Episode of Chopper Plus - Fuyu ni Saku, Kiseki no Sakura

The movie is a retelling of the Drum Island arc with new music and animation. Vivi has been removed from the plot while both Nico Robin and Franky, who joined the crew after the Drum Island arc, have been added. The movie also has the Straw Hat's new ship, the Thousand Sunny. It has been stated that Oda will be creating a new character for this movie, Wapol's older brother, Mushul, who also appears to be a Devil Fruit user. 
(Source: Wikipedia)

One Piece: Mezase! Kaizoku Yakyuu Ou

Luffy and crew takes on Arlong's crew in baseball. Announced by Bon Clay and Buggy.
(Source: ANN)

Tokyo One Piece Tower: Tongari Shima no Dai Hihou

A Tokyo One Piece Tower exclusive film. It's a tie-in to a real treasure hunting event in collaboration with Takarush Corp. for a limited time called Treasure Hunting: Tongari Shima no Daibouken. During this, you’ll decipher the mysteries of ancient documents found by Luffy, Usopp, and Chopper, and then set out to find the nest of the mysterious animal known as Tongari Ton!

The film itself begins at the end of your treasure hunting adventure at the Tokyo One Piece Tower, where the Straw Hat Crew are tricked into opening a chest in a cave thinking it's where the Tongari Island treasure is.

One Piece: Taose! Kaizoku Ganzack

While Luffy and his crew of Zoro and Nami are starving on their small boat, they are attacked by a large monster. Nami is taken away, while Luffy and Zoro wash up on shore. There they meet a young girl, Medaka, and learn of the sad history of the island. The evil Pirate Ganzack has taken away all the men in the village and enslaved them, including Medaka's father. Now Luffy, Zoro, and Medaka must infiltrate Ganzack's base in order to rescue the villagers and Nami. 
(Source: ANN)

One Piece: Nenmatsu Tokubetsu Kikaku! Mugiwara no Luffy Oyabun Torimonochou

In an alternate reality world that resembles Edo Period Japan, Luffy acts as a member of the police. This is made up of two adventures: in the first, Buggy makes trouble in the town; in the second, a mysterious girl named Vivi appears (aired after Episode 253). This special contains several cameos from characters throughout the entire series. A second pair of episodes were aired after episode 290, continuing this story, as part of the New Year's special.

One Piece: Yume no Soccer Ou!

Luffy and his crew take on the Villain All-Stars in a game of soccer in order to become the Dream Soccer King. The game comes down to a pk tie-breaker shoot-out with Coby as goalie and Helmeppo refereeing.
(Source: ANN) 

One Piece Movie 1

Woonan is the legendary Great Gold Pirate, earning the nickname after accumulating about 1/3 of the gold available in the world. Even after his disappearance, the tales of his gold being stashed away in a remote island continue to persist, a juicy target that other pirates lust for.
One of the pirates going to great lengths to attain the treasure is El Drago. He and his crew have hunted down Woonan's former crew members one by one, and along the way, they find the map that will take them to the hidden island.
The map is not all they come across; they also manage to come into contact with the straw hat pirates. After a short battle, Luffy and company are robbed and separated from one another. Now they must find a way to make it to the island before El Drago does and take the legendary treasure for themselves.

One Piece Movie 4: Dead End no Bouken

Luffy and crew arrive at the harbour of Anabaru. The local casino is holding a competition in which the winner will obtain a huge monetary reward if he reaches the finishing line first. Nami is elated and decides to participate in the competition. However, there is a conspiracy going behind the competition and the mastermind is an ex-military commander, Gasparde. His plan is to lure all the pirates to the military base and send them to their deaths. Luffy and gang have to overcome the numerous tests and tribulations along the way to complete this dead-end adventure.
(Source: ANN)

One Piece Movie 6: Omatsuri Danshaku to Himitsu no Shima

The Straw Hat crew obtain an advertisement for a recreational island on the Grand Line run by the Baron Omatsuri. Luffy decides to take this opportunity to kick back and relax. Unfortunately, when they arrive at the island, they are asked to compete in contests through unity for access to relaxation. However, there seems to be a mysterious air on the island, as the Straw Hat Pirates begin to fight amongst themselves, while Robin, Chopper, and Luffy individually search for the secret behind Baron Omatsuri's island.
(Source: ANN)

One Piece Movie 7: Karakuri-jou no Mecha Kyohei

The Straw Hat crew salvages a treasure chest from a sinking wreck, inside which they find an old lady. To get the pirates to take her home, she promises them the treasure of a golden crown on her island: Mecha Island. Upon arrival, the crew is attacked by the lord of the island but he has a change of heart and decides to seek their help to solve the mystery of the Golden Crown.
(Source: ANN, edited)

One Piece: Oounabara ni Hirake! Dekkai Dekkai Chichi no Yume!

The story opens on Pirate Zap's ship, where two of his crew, Bonnie and Max, are tired and want to escape, but unfortunately they have no money. Three children were being held captive on the ship overhear them. The eldest, Amanda, who's father was a pro treasure hunter, knows the whereabouts of a great treasure, and offers them a deal. If they help them make a clean escape, they could take all the treasure they wanted. They agree, and the five of them barely escape and make it onto a small island where they meet Luffy and his crew. Unfortunately they were pursued and Luffy and Amanda are captured and brought back to their boss, the head of the Bayan Pirates, who is also after the treasure. Now Luffy and the others must battle the Bayan pirates and find the treasure that Amanda's father had left for his children. Amanda, who has always resented adventure and treasure because her father was constantly gone in search for it, finally understands his feelings. 
(Source: ANN)

One Piece: Mamore! Saigo no Dai Butai

For many years, Ex-Marine Lieutenant Randolph and his troupe have put on a play aboard his ship. Having lost his family to pirates, Randolph wishes to put on plays that will give courage to those who have also lost their loved ones to pirates. Unfortunately, Randolph must retire soon, and he is now giving his last performance. Luffy and his crew come to see the play, and somehow manage to take part in it themselves. But from Randolph's past comes a vengeful subordinate with a diabolical plan who has finally become commander in order to capture Randolph. Luffy and his nakama now must prove to the people that not all pirates are scum, and protect Randolph's final farewell performance from the bitter commander. (aired after Episode 174)
(Source: ANN)

ONE PIECE FAN LETTER

Two years after the Paramount War, the Straw Hats are about to reunite on the Sabaody Archipelago. At the same time, a girl who is head over heels for Nami is trying to hand a fan letter to her before the group leaves the island.

(Source: Crunchyroll)

One Piece: Jango no Dance Carnival

Luffy and his crew are on Mirror Ball Island during a dance carnival. They are spotted by Marines just as Jango the hypnotist is running from them. Luffy and the others are caught up in the dance carnival as Jango, in his desperate attempt to escape, hypnotizes the entire island to dance the night away.
(Source: ANN)

One Piece Movie 5: Norowareta Seiken

Luffy and crew go to an island searching for a legendary sword, said to be the most expensive in the world. Soon attacking marines and beautiful maidens split the crew. Zoro betrays the crew to help an old friend, Luffy and Usopp wander through a cave, and the rest help a village fight marines. When Zoro defeats Sanji he takes the sacred pearls that are the only defense against the evil sword that will plunge the world into darkness. 
(Source: ANN)

One Piece: Umi no Heso no Daibouken-hen

The Straw Hats encounter a city in the middle of a whirlpool, called the Ocean's Navel, that is being destroyed by giant monsters. These monsters supposedly protect a treasure capable of granting wishes, but in the process of defeating these guardians, the crew ends up releasing another evil.  (aired after Episode 53)
(Source: Wikipedia)

One Piece Movie 2: Nejimaki-jima no Daibouken

Informed by the Thief Brothers his ship has been stolen by the Trump Kyoudai (Trump Siblings) who have set up base on Clockwork Island. Monkey D. Luffy, Captain of the Going Merry and aspiring Pirate King works with his crew - Ussop, Zoro, Sanji and Nami to battle their way up Clockwork Island to reclaim their ship.
(Source: ANN)

One Piece Movie 3: Chinjuu-jima no Chopper Oukoku

The crew comes upon Crown Island where the animals can talk and they makes Chopper their new king. But there are human hunters there also looking for the legendary horns that will give the person who consumes it immense power. Luffy and friends must stop them from destroying this animal kingdom.
(Source: ANN)

Luffy, Law

It is the Great Age of Pirates. This is an unknown event that took place after the battle of Wano Country.

(Source: YouTube, translated)

One Piece: Straw Hat Theater

Straw Hat Theater is made up of five shorts that aired alongside One Piece episodes 279 through 283 in October 2006. They are based on Oda Eiichiro's side comics that were drawn when he was given three sheets of blank paper by his editor and told to draw anything.
The first short is about Chopper Man infiltrating the lair of the evil Dr. Usodabada. The second short is a news report on what food was like for the Straw Hats before Sanji joined the crew. The third short investigates the hypothetical situation of "if the Straw Hat Pirates were Obahan, who would be the strongest?" The fourth short is about the bosses of the Luffione, Zorocia, and Sanjino families fighting for control. In the fifth short, all of the Straw Hats are carefree monsters.

One Piece Franchise