From feats, I would say Tobirama since he created many programs in Konoha that other villages later adopted. He created the Ninja Academy, Chunin exam (probably Jounin promotion requirements too since he did for the first 2 levels), anbu black opts, and police force. He put the rules first and thought of the big picture (the whole village) instead of any singular clan. He even had to scold Hashirama after he tried making Madara the Hokage without asking the council or members of the village for their opinions.
I do think that Minato would have been the best Hokage out of 1-6 if he lived on. He put fear in others like Hashirama (fleet on sight orders were given to earth ninjas during the 3rd war), had the smarts like Tobirama, had a good heart like Hiruzen, was pretty strong physical like Tsunade (not to her extent. He nearly cut thru Bee's tentacle with no leverage and was going to strike A in the same fashion even though A had his lightning armor active. Plus SM gives him 1 hit KO strength), and is well respected plus have no KKG like Kakashi.