Oh yes an anime/manga question. Hope we see more of this. Muser francistagbo below gave a really good ranking of the overall speed of the seven Hokages. But I am not sure I agree with the top 2.
He ranked Naruto as being faster than Minato. That is definitely true when it comes to running and fighting speed, as Naruto in Kyuubi mode has incredible Chakra and hence his speed is unmatched even by the Raikage. However, Minato has an exclusive Jutsu, the Hiraishin, where he can teleport to any where he wants. With teleportation, the factor of distance and time is eliminated, and hence speed is of no measurable here.
Therefore, if it comes down to the fastest Hokage, in say, a 100m 'running' competition, I will bet on Minato reaching the finishing line first. But if it is about fighting, then Naruto will probably have the upper hand if he can force a close combat with his father.
Good question!