Furry-Within

So Vote and let's say why we believe so!

l'll start us off..
ln my opinion, Zack is the biggest death, l believe, the factor are that: You play as Zack, He is the catalyst of the whole story, and, well.. he's cute!

So, the first reason: You play as him.
Throughout Zack's story, you watch as he impacts others lives, making friends.. to see his accomplishments, and also in the end, how he dies.. how the memories of those he kept close to started to fade away, until the closing Cinematic where he dies.

Catalyst to the story: He was the one who went to Nibelheim with Sephiroth, which started the whole thing with Jenova and all.. Without his death, essentially Cloud wouldn't have joined AVALANCHE Because of his hate of Shinra, meet Aerith as he did, THUS endangering her as so.

Third, he's cute. Seriously, just as his petname implies, 'Zack the Puppy.' lndeed l say that his death had the biggest impact.