SHIT, I lol'd. I think Ino. Her ability is pretty unexplored and could be really powerful if used in the right ways. It's just that her character is relatively weak
See, Kishi wants us to think it's Sakura because she's one of the main characters, and it probably is.
But to be honest I don't give a crap about her development. I'd much rather see Hinata's potential being utilized than Sakura's.
Tsunade > Any Hyuuga
Sakura in future > Tsunade
Its clear that Sakura has the biggest potential. Did you heard from any manga character than Hinata can become stronger than Tsunade? I didnt.
So, obviously, Sakura.
Sakura
Tsunade Student
So if she gets all her abilities (which it might look that way)
Katsuya
CRB
Massive Strength
Fighting Med ninjutsu
Kakashi said in part 1 that she had a talent for genjutsu in part 1
so lets say she might learn it in the future, who might teach her? Kurenai
so She can learn genjutsu
and every ninja has an element affinity and jonin have 2
so add that
so what you could possibily have is Sakura with:
Best Med Ninja (after tsunade dies)
Katsuya
CRB
fighting Med ninjutsu
Genjutsu
Massive strength and taijutsu ability
and 1 or 2 elements
Sakura has crazy potential