Oh yeah One Piece is an investment for sure. I got in when it was maybe like... four years old, lol, it's more daunting now.

Actually, if you are indeed intrigued by it, I'd recommend you watch the Strong World movie. Aside from crewmembers that joined, it doesn't have any spoilers, it's self-contained in terms of plot, and it displays a pretty accurate sample of the tone of the main storyline (humour, characters bonds, reactions under stress, combat. etc).So if you watch that and like it, you'll probably like the show/manga, if you don't, well, then you'll know :P