I - Princess Sarah. I enjoy seeing her modern adaptation in various modern spin-offs. The pink hair with the gold dress combo is nice and she's sweet and is the ORIGINAL Princess Sarah (there's another Princess Sarah in FFIII).
II - Maria. She's a mage with a bow and arrow... if you build her that way that is. I did. And she starts out oriented towards that. Proto-Rosa.
III - Aria. Her theme is great.
IV - Rydia. Proto-Terra.
V - Faris. She's a surprising character, if you know what I'm saying.
VI - Terra. In combat she's just ridiculous. She's tanky and has good ATK because of her equipment (can equip swords and heavy armor) but also has a high MAG stat (I know all of this can be influenced by equipping espers, but still). Celes is pretty much the same, but Terra is just special because of her green hair, search for love & meaning and also being part-Esper. She seems delicate but is actually insanely powerful.
VII - Aerith. She's kind of like Terra, no? She's "special" but also seems kind of meek, but harbors great power. I love these kinds of characters. She's not a sexual object like Tifa.
VIII - Edea. Badass sorceress with a cool look.
IX - Garnet. A girl who wants to be free, I could relate at one point.
X - Rikku. Spunky, smart and uber cute. She should donate some of her personality to Yuna.
XI - Shantotto OF COURSE. She's an adorable little tarutaru... that's evil and powerful as . And she isn't the sad sack type of evil like Sephiroth, this little bad girl is arrogant, condescending and the best at what she does. Also, she cackles maniacally.
XII - Balthier. Sexy bad boy; great voice actor. Now that I think about it, he kind of looks like Joseph Gordon-Levitt.
XIII - Lightning. She's a badass and an all-rounder stat-wise.
XIV - Minfillia. Because she's the only one I remember. Cool character design. Her and Lightning would also probably get along great if they met. I imagine they would come up with military strategies for fun.
XV - Noctis. Watching him grow up to be a man by playing his adventure, I feel like he's the FF character I got to know the most out of all these years playing FF games. Amazing character.