Out of everyone that is now currently alive as of chapter 600 of the magna's
Idk after that.. Theres a huge gap between these characters and everyone else except the 5 kages. Even then, the 5 kages aren't all that strong except A and Tsunade.
Other than that, Mu, Kakashi, Guy, Gara, Onoki, the Second Mizukage, A, Orichimaru, Jaraiya, Negato, Minato, Sarutobi, Hashirama, Tobirama are all also strong ninjas
I feel sasuke needs to learn more and get his feelings straight before he get on my top list