It is widely believed in Konoha that the Fourth Hokage is the greatest Hokage ever. Let's take the word greatest for the purest sense: it could mean he's the strongest, or the most popular, or the most heroic, or the most admirable, etc. The word greatest is too vague. But it is possible.
I agree that the leader of Akatsuki must be the strongest. The one to have the potential to be the strongest by the end of the series would probably be Naruto, as well.
But I will list the few people who may be argued easily by just about anybody to be the strongest: The Jinchuurikis (noteworthy is Naruto); The Sanins; The many village Kage; some member of Akatsuki; some tailed beast (noteworthy is Kyuubi); or some character we have yet to see; or a member of Team 7 (since they probably have the potential to surpass their sensei, the Sanins).
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"Foolish little brother, if you wish to kill me, then hate me, detest me -and survive in an unsightly way... Run, run and cling to life.”
Edited on 02/24/2006 5:40am