For me it has to be uh...
Cloud.

Spoilered because people might not like my opinion:
(SPOILER)
I'm sorry but he's just too overwrought all the time. And while I understand Squall is a teenager with his annoying hormones of annoyingness (which actually makes him likable to me), Cloud has to be the one with the total woobie-like nature and angsty teenage-type hormonal traits that just don't stack up because he's TWENTY-ONE.