This is obviously a popularity contest, not an actual fight, seeing as Vincent, Squall, and Cloud all made it to the semi-finals. We all know Auron would win a battle tournament, since (SPOILER)Even death couldn't stop him.
As for my vote, God's Hand + Deathblow > Renzokuken + Lionheart, not to mention tough chick > emo kid, so Tifa hands down.