I think my heart was set on Auron imediately when I first knew the list. I like Auron, because he is tough and wise, with a hint of mystery. My second vote would go to Cecil.
Maybe it's just because I haven't played a lot of FFVII yet, but I don't find Cloud that appealing to me. I think he's also a bit confusing, because first he seems like a tough boy, but then suddenly he's not. :/ I mean if I could vote for Sephiroth, I'd do it without a blink, or even Red XIII, and I have known those characters for much less time than Cloud. Also, what I remember from Advent Children, I didn't really like Cloud on that, so...
And isn't it a bit unfair to have Cloud on the whole competition anyway, as this is after all FFVII forum. You can't say that Auron wouldn't be doing better, if this was a FFX forum.