There's quite a many characters who I really like in KH, and I can't choose between them. I like seeing Aeris return, and her character remained nice and sweet, and she wasn't trying to annoy Tifa this time, so I didn't have any problems with her. Sora is the main character, and I can identify with him rather well. Another probable pick. Kairi and Riku are good characters too. As for Disney characters, I like Ariel and Belle. Ariel's personality is fun, and her being a party member is another plus. Belle's also a nice character, and I really like her dialogues in Hollow Bastion's library, especially when she speaks about Ansem. Way to go, Beauty!

BTW in Finland, Riku is a boy's name. So it's not an imaginary name. I've never heard of anyone called Rikku IRL, though.