1. Namine - she is the most wholesome and helpful one, without ever fighting or owning a Keyblade. Also, I like her simple, feminine design - it's beautiful.
2. Xion - I just like stuff and people related to the melancholic themes, and anything related to Roxas and TT is exactly that. Plus, I find shy gals with problems extra interesting, sometimes heartmelting, lol.
3. Aqua - she is the coolest/hottest one when it comes to her looks. Her abilities are pretty unique too. But her persoanlity is just... boring to me. I respect her for what she does, and having more people like her IRL would surely be great, though.
4. Kairi - she is too inconsistent, and being THIS "cutesy" makes me take her less seriously as a warrior. At least when it comes taking on more serious threats than a typical Heartlesses.