Im a big fan of naruto and one piece, though i do find the strenching of storylines over vast amounts of episodes irritating, while no where near as bad a DBZ, one piece especiaily can have quite long periods of not much advancing the plot.
Theres sites out tehre with all the one piece and naruto manga's translated and they are a good read. much better than the anime imo
one piece seems a little more childish in parts, and gets more "silly" sometimes, some people like it, some people dont. Of course, both are aimed at japanese schoolkids, so dont expect any supermature themes or w/e )
I wanna get hold of some of the games, going over to japan next year, so should be all good.
I was reading somewhere, that a american company has took on one piece, but from what i saw, they have ruined some of the main characters, sanji seems to have a lolipop instead of a cigerette etc, which doesnt bode well, but this is half remembered from months back, hopefully im wrong.
anyway, i love em both, watch em when i can, i do recommend the manga's