Of the many many countless anime I have watched, One Piece is no doubt the best anime I have watched and this is by no means an exaggeration. To say anything else would be an understatement and nothing more.
The character development in One Piece is insane. You would expect the main character of an anime to be given the most screen time, the focus being on them majority of an arc or a saga. But surprisingly this is not the case. Every character, major or minor, if relevant to the current story line will be given a considerable amount of screen time. There are even
episodes where Luffy isn't even included. It honestly feels fresh because it is like you are watching the life story of multiple characters at once, like you are a spectator not to the happenings of a certain person but what is happening in the world in a more generalized manner.
You learn about the backstories of every single character, even the most minor ones. Just when you think you know one of them or a backstory is over, you are hit with another one. Eventually you will come to think from their perspective, as if you are THAT character. And I cannot stress this enough but One Piece ensures that no character, after introduction is or ever becomes irrelevant. No matter how minor, no matter even if they have the least least amount of screen time... they will play their role. Imagine seeing that random character like four hundred episodes back that you almost forgot about just randomly appearing and pulling the big strings? That is exactly what I mean. There is like eight hundred if not a thousand now and yet every single one of them remains relevant to the story.
The anime with all it's arcs focuses on a lot of the problems that our world is facing today. In a way, it gives insight of the people who are both directly and indirectly suffering. I feel like it is Oda's way of contribution, or a sense of duty to spread to the viewers the world's plight whilst providing entertainment of some sort. Poverty, slavery, war, corruption, oppression, crime, murder, human trafficking, disease, hunger, you name it. Every single one of them is included and you cannot just help yourself but to care.
Then there is the fact that, even though it has been so far into the anime I fail to find any form of plot holes whatsoever. Even if there is any, every single one of them has been explained later in the story through unimaginable plot twists (so unimaginable and unexpected you'd be going crazy) or in a way that you could never ever guess.
Much like character building, the world building is also massively vast. The story literally takes place focusing on the entire world. Snowy plains, mountains, forests, Arabian deserts, urban settings... even the worlds underwater and the sky itself. And each island visited by the characters are well-made with detail and what not. I can say without doubt that a proper full fledged MMORPG world could be made with the distinguishing details and thought put into them by Oda.
Whilst doing all this, the anime hasn't failed to remain creative. There are so many personal touches, you can almost see the depth of imagination put behind their creation. It is much like a world of a child's creation unlike that of an adult. Much like how children often end up creating things you'd never expect unlike an adult who would have more "mature" or "life-like" creations. It's sometimes interesting just to see the background over what is going on in the anime, that is the plot.
Speaking of plot itself, you'd think a pirate anime would be all about stealing and ransacking and just fighting each other to rise to the top... it's anything but that. We aren't seeing the story of Monkey D. Luffy here or any of the other main characters. No, we are seeing the history and the events of the massive world created by Eiichiro Oda. The world of One Piece. And then finally there is the anime openings which will forever remain memorable to me.
Do not let yourself be discouraged by the massive amount of episodes. Start the anime when you are not very busy yourself. Take it from someone who claimed One Piece was horrible because of the art and how long take to catch up. It has been a ride, and even more so by commenting on every episode and hosting discussions, debates.
I would definitely delete all my memories and re-watch this anime from scratch, should that have been possible.