Yuffie. She had sly ninja goals and didn't die on disc 1. She didn't talk much. Plus you have to leave her behind to get her.
"Come with us or not. Whatevs. *Walks away"
Tifa is nice and all, but.. eh. Her, Vincent and cait sith don't make my go-to 3 team, ever.
Cloud, yuffie, Barrett. That lineup counts for a lot, imo. Dps{cloud}, utility (heals on yuff) and mp-drainer (barret's 2nd limit)