Yuffie and Aeris were both way too kid-like for my liking. Yuffie had her reasons, obviously she's still pretty much a kid - but she's still a bit too hyper for me anyway, even though I'm only 19 myself. Aeris... *thinks of a way to put it lightly* She totally threw herself at Cloud. Like... ugh, get off my main character, dammit. >=/ She seemed very ... uh... y'no. If you haven't picked up my opinion, then don't worry. =P

Tifa, however, was the shy, quiet, deep type. I liked that. So she was the one for Cloud, in my games.

Before anyone gets into a big debate about Tifa vs. Aeris (should it happen), I would like to kindly point you to the addition to the FAQ I made a few months ago to solve any dispute.