Steven is my top followed by Cynthia. I think they both made good characters. I found their designs appealing and their teams to be an interesting match up to their character.
I really dislike Alder and Iris though and I usually just pretend they never happened. Also Wallace was a poor change because his team is ridicuously easy to beat, but I really enjoy Juan taking his place as gym leader and I like the slight difference in character for Steven.