The coolest one was Seifer, personality-wise. And if he was a real person, he'd be damn hot...

As for the girls, I liked Quistis. Beautiful, smart, serious, down-to-earth. But I'd like her even more if she'd been a bit more confident, like Rinoa. But that's exactly what I liked about the chars in that game. They were human. With both their traits and flaws.