To me the 3 Best units would include:

1) A fast game turn 1 winner when it comes down to bp mown down for like swb/rogue

> eg. Kimimaro Halloween/Shark Kisame BT

2) A most versatile lineup esp for gnw/xgnw/db

> eg. quite some options there is no one for all meta anymore i think,

anything from the still applicable/countering meta like the above or madara gnw bt, all the p2w op

to new units like angel ss, kkz creation, sage kabuto bt, shisui kimono bt is breaking in.

3) Arena-non-bp lineup, 1v1 or 3v3, now this section i hardly study enuff and is fun for even more varied possibilities