I am going to vote for Shingeki.
The only two options i had would be to choose or Hunter x Hunter or Shingeki ... but going to choose this one, cuz even though i only follow it for quite few time, it's really interesting and has a lot of potential. And Hunter x Hunter was on Hiatus for really a lot of time.
I am not going to vote for either Naruto or One Piece. I mean, them reaching this phase isn't even fair. Specially One Piece, because for most of the year it was terrible and really boring ... even though Naruto at some points, might have been even worse.
They weren't that strong this year ... and if it was up to them and Toriko, i would happily vote for Toriko, since even though it had a pretty boring part, it had also pretty interesting moments.