Demyx was funny, but sometimes he didn't know what to do. He was like "I know there is something I have to say but I don't remember what. Give me some time, man!".
I think the best was Zexion. He was polite but acid sonetimes. He was that good that he himself forgot that he could not feel. You know he was really afraid of Riku Replica. That was pointless. He had not need that act, realy. He could prepare to fight him but he freaked out.... So he died.