1.- Itachi: Genius, MS, Amaterasu(can only be absorved before it hits and you have to be raikage's fast to dodge, if it hits only a seal of fire can be used but the dmg is done), fastest hand seals, Susano'o (with the strongest spiritual and defensive weapons), Really fast movement and clone usage, best genjutsu with eyes and fingers, and we still dont know what he gave to naruto, and YES Madara and Pein feared him, konoha was attacked after his death. On cons he was weakened as nagato.
2.- Nagato: Six paths (amazing!), affinity with all elements, rinnegan, large reserve of chakra.
3.- Kisame: Largest reserve of chakra, Samehada, chakra absortion and negation, Suiton affinity, inmense strengh.
4.- Orochimaru: Great intellect, forbidden jutsus, kuchiyose no jutsus (snakes).
5.- Deidara: C2, C4 best at the art or explosions, could manage to fight everyone in the air, only down is that he is too weak to dojutsus techniches such sharinghan gen or chakra perception.
6.- Kakuzu: Lived for generations, lot of hearts, dominant of many elements, taijutsu master and good body usage.
7.- Konan: Papers, could hit madara, explosive and air techniches.
8.- Sasori: Puppets, poison weapons and techniches, body container change because of heart, 3rd kazekage puppet and metal sand.
9.- Hidan: Great Scythe skills, inmortality (not that good), jashin ritual.
10.- Zetsu: 2 personalities, cloning master and best spy. Dont know much about him yet, in manga he could take dna and clone the chakra of the user (so great at infiltration too) He is probably gonna be top 3 at the end.