*Discounting the Sage of the Six Paths and Edo Tensei*
1) Hiruzen Sarutobi:
I'll probably get some flak for this. Anyway, he was trained by the Hashirama and Tobirama, and was stated to be stronger than every other Hokage in history. Called the Professor since he was a master of all shinobi aspects, which was shown by the fact that even at 69, he had a rating of 5 in Ninjutsu, Genjutsu and Taijutsu. In his prime, he was said to know all existing techniques within Konoha, and showed the ability ro use even S-rank Fuinjutsu like the Dead Demon Seal. Even after besting Orochimaru and the two Edo Hokage, his summon Enma said his performance was 'miserable' compared to what he once could do. Orochimaru and an ANBU that was watching said that in his younger days, he had a massive amount of powerful chakra, which when released caused the surrounding air to become denser.
/wall o' text
2) Naruto Uzumaki:
This one was tough. Minato, Hashirama and Madara were all picks I considered. But Naruto defeating multiple Tailed Beasts, as well as other powerhouses like Mu, the Six Paths of Pain and the 3rd Raikage just made him the clear choice. You all know what he can do, so I'll end it with the fact that he still has plenty of room to grow, such as combining Kurama's power with Sage Mode like he's shon once before.
3) Minato Namikaze:
Again, another tough decision. This choice was made partially based of the two conversation Jiraiya and Tsunade had about Minato, in which they agreed that he could have surpassed all shinobi who came before him and was rather close to doing so; A stated something similar. He defeated the series' main villain with relative ease and swiftly, and even A and his 'perfect Jinchuriki' brother B coouldn't touch him when fighting together. He showed exceptional skill in Fuijutsu as well,was noted to be the fastest shinobi in history, good strength and was noted for his rare, very high intelligence. Namely, the Flying Thunder God technique is a big reason why I picked him over Hashirama. Come on, instantaneous teleportation and already insane speed makes for a deadly combo unless you have some kind of defense like the 3rd Raikage's skin, which few have.
4) Hashirama Senju:
Defeated EMS Madara partnered with Kurama. That's just badassery incarnate. Only natural Wood Release user and had the innate ability to perfectly control multiple Tailed Beasts and noted for having an incredible physical energy/life force. Damn. Hailed as the strongest shinobi in the world while alive and said to be exceptional in all areas of combat. Did I mention he defeated Madara and Kurama? Had a medical technique similar to Tsunade's 'Strength of a Hundred' technique, allowing him to heal his own injuries without hand seals.
4) Nagato:
Yeah, two guys at the #4 spot, deal with it. I couldn't separate these two, as they're about equal in my book. Even with weakened ability with his techniques, Nagato's Six Paths just about soloed all of Konoha at once, not to mention destroying it with Shinra Tensei. Nearly killed 2 OP Jinchuriki by himself, despite being crippled and even then almost took out Naruto, B and Itachi. His combination of abilities make him nearly unstoppable.
5) Madara Uchiha (not counting Edo Tensei at all or his enhancements):
Uchiha HAXing had to to be here. =P
Anyway, first Uchiha to ever awaken the MS and EMS. Survived all his fights with Hashirama, could control Kurama and stated to be the strongest Uchiha of all. Exceptional user of Fire Release and Sharingan mastery. Showed impressive speed and Taijutsu too. Susanoo is just crazy good at defense and he's currently fighting all 5 Kage (though to me, that's dampened a bit by the fact that he's been enhanced considerably beyond what he could do in life).
