One Pace is a fan project that has been running since 2013 and it has the goal of fixing the One Piece Toei series.
Basically, in anime, they will have to drag out scenes or make filler episodes (additional, useless content) as to not catch up to the source material. One Piece, very sadly, chose to drag out scenes, so now the episodes are boring and a slog, especially after Episode 516.(Timeskip)
One Pace removes all of the filler episodes and drawn out scenes, and it does it flawlessly. The music, instead of cutting out when a scene ends, flows from one scene to another, making a smooth experience. The quality is also surprisingly good, with atleast 720p for every arc.
One Pace is not finished yet, and won't be until the original series is, of course, but it is still amazing. It shortens the 1100+ episodes into 500. If you want to experience the story of One Piece but are busy, I would recommend the manga, but if you want the amazing music and animation of the anime, watch this.