I believe so.
Yata Mirror seems so OP. A number of strikes and attacks can he dealt in the 5-10 minutes Itachi can keep up Susano'o, and I think this is what puts Itachi in my top 15, MAAAAYBE top 10.
Daisy slightly disagrees with you. While I agree that the Yata Mirror is quite a haxed weapon (along with totsuka), It doesn't make Itachi "invincable" The miror will undoubtedly block anything that comes its way, but it will only be blocked if it hits the mirror. If it misses and hits the Susano'o itself and breaks it or if the Susano'o is hit with an attack such as Kirin or Tailed Beast bomb that would have a blast range that is greater than that of the mirror and could possibly encompass the entire Susano'o in it's blast, then Itachi is
f**ked. And I don't remember hearing about the mirror guarding against physical attacks. It think either a direct attack (like a punch from Tsunade) or a blow from another Susano'o would be the best and most surefire way to go about combating Itachi's Susano'o. Just whach out for that
HAXXED AS ALL :devil:
COWABUNGA F**K!!! :devil: Totsuka Blade. . .
And concerning the whole top 10 thing. I would put Itachi (disreguarding his jaded wankers) in MY top 10, but NOT in my top 5. And just for the sake of no flaming, I won't disclose where I placed Minato.