By better duelist, do you mean whose more knowledgeable in study of martial arts, who would win in a no holds barred fight, or who would win if they were duelling in say contest conditions, where bouncing off the walls is most certainly not allowed?

I mean Count Dooku had an interesting style of dueling

But I think Yoda might be

As a duelist, Dooku. Yoda is a great duelist but is dependent on the force to do a lot of the legwork at this point.