ok, i haven't read all of these, but i voted One Piece because of ONE reason, and one reason alone.
Sense of progress. One piece is the only manga that survives weekly in my book.
When i read a new manga from the beginning they can become as engaging as One Piece. but when i catch up, i get tired of them in less then a month (Always in less then a month except Op) however, i have been reading One piece is up in 2 and a half year, and i still care about it. it's because they have advanced since last time. when i got to the last published One Piece they were in the middle of the first arc and had just gotten a brand new ship, now they have reached the middle of the grand line, (halfway trough) the ship is beginning to get old. In dragon ball however, the difference is that during the sayian arc goku had 8000-9000 in power level, and in the Freeza arc he had about a million.
In Naruto, the quest was to become hokage, and now the town is annihilated and naruto pretty much proved he is the strongest in the village. and then some other guy became hokage and there is some moral issues with sasuke.. and akatsuki is planning somethi… JUST BEAT UP THE OLD MAN AND BECOME HOKAGE BY FORCE. (Just some louzy shonen example but if someone find a 300+ chapter manga with the same sense of progress as Op, please tell me)