Hanabi, should be the clan leader. Neji is in the branch family and it would be nice if he was in the main family but as it stands he can't. Hinata would be the logical choice given that she is the elder of the Hyuga sisters but she does not have the qualities that would make a viable leader and a competent one. Through out the manga she has predominantly been a follower her sister Hanabi on the other one is the complete opposite of her sister in every way. I would go even further and speculate that Hinata realizes this and would cecede leadership to her younger sibling unless the chosing of Hyuga clan is done via the Clan head and Elders in a matter such as this.
respectfully, Usagi