Guess I'll have to pick Cloud -- if only just to counter-balance all the Sephiroth-love going on here.
I love 'em both, but two things immediately come to mind:
1) Cloud is Vincent's best friend -- and Vincent takes the cake in my humble opinion.
2) Sephiroth is Hojo's son -- that is a negative that goes without further elaboration.
By the way, great character synopsis in the OP, hikkiFM!