I'd probably have to say Kakashi and Gaara tie for the top. I can't decide between the two, because I love both voices. I also love Gaara's seeiyu in Chrno Crusade (Chrno) and Kakashi's seiyuu in Chrno Crusade, even (Aion). But if I HAD to pick, it might be Gaara. Every other seiyuu in the series is wonderful as well.