Most likely Tobi/Obito = hes feats are inhuman.
The fact , that he can controll Gedo Mazo is a proof for that , I doupt , that any other could controll it.
But Also Itachi , since Itachi was practicaly extremely talented at a young age = more talented than Minato or Kakashi of the same age.
I could say , that Shisui might be even more talented = since Itachi looked up to him , like older brother.
There might be a chance , that Shisui trained itachi to this level or helped/guided him = they seemed to be very close.
Sasuke is most likely more talented , than Itachi was at the same age = most likely will surpass Itachi in the future.