Ok everything about this anime it's outstanding, in my opinion One Piece is the Best shounen anime Ever.
Now let us start:
STORY: It's story is Adorable a masterpiece that was named One Piece, the real deal and the good part is not only about that pirate king that hid one treasure, but it is those countless men that went out to search for it! Thrilling and exiting a story that had many anime-watchers riveted.
ART: The art is Awesome the animation was fixed a little after some 200 eps(or so) every detail every part that is important for the viewer to understand the situation is being drew excelently
CHARACTER: I think that the characters are one of the most outstanding things in One Piece. For starters the main character the one that wants to become king of the pirate is UNIQUE, moreover other characters are so weird and peculiar and by using them the anime is far more intersting and fun.
ENJOYMENT: Not much about the enjoyment i just have to say that when an episode finishes i was like: "i want more One Piece!!"
Now to conclude every thing about this anime is so well organized, the anime is perfect in sooo many genres it has Great action- Hillarious situations- Sad situations- Many teachings- Tremendous adventures
Watch it... You MUST watch it.