Gai vs Itachi? Itachi win, no doubt about this. Gai can "dodge" Sharingan while looking at feet, but Itachi can do a bomb duplicate and good bye Gai lol. I wonder if you need to look to get caught in a genjutsu beside the sharingan if you do, let bet itachi has his toes nail paint now haha.
Anyhow, Itachi vs Sasuke gonna be hit n dodge genjutsu beat genjutsu... seem boring.
Tobi vs Naruto n compagny seem more interesting.
Pein secret is a most now but pa has to get to tsunade first so will take a while.
Kisame vs Suigetsu, This is the most interesting fight, to see Suigetsu in battle against The infinite chakra eater Sharky.