Best final boss in a Nintendo game

[curl-6]

There are so many greats, but if I had to choose just one, it would have to be giant baby Bowser from Yoshi's Island.

It's just so freaking epic. From the badass music, to the sheer scale, to how technically impressive it was for the time. (I like to see it as marking the transition to 3D that would come to fruition the following year in Mario 64)

Honorables mentions go to DJ Octavio and Metroid Prime.