The Fastest Ninja in Naruto?
Technically, Minato Namikaze is still titled as the fastest ninja. Take a look at the signature Ninjutsu of Minato, the Flying Thunder God Technique. It's classified as one of the Space-Time Ninjutsu, which are techniques that allow the users to teleport to another location instantaneously. No one can exceed the speed with using only physical power.
If you're talking about the comparison of raw physical speed, Fourth Raikage takes the lead. Naruto Uzumaki is still pretty fast, but he only surpasses the Fourth Raikage when he's in Nine-Tails Chakra Mode.