Best Power-ups?

[xcoyote]

The best is most likely Rinnengan because of its versatility and it kinda has unlimited potential since it gives you mastery over all 5 elements.
My favourites are SM and Gates.

 

[RikudouMadara]

Sharingan/Rinnegan easily.

 

[Naijakid]

Getting katsuya is also a powerup

 

[awesomeseimei]

SM, especially speed/strength buffs and Frog Kata. And Gates.

 

[Boston Rob]

Sharingan/Rinnegan easily.

this, bijuu could be nr1 but - 3tm > bijuu

 

[Ahmed1993]

Sharingan/Rinnegan easily.

Same here.

 

[Flakez]

My fav are SM, BM and BSM.