Kobe and it's not even close. Duncan is the best PF of all time too, but Kobe is all around a much better athlete, so has to be the better player. They just asked this recently, may have been on NBA TV, there were 3 former players on the panel who played against/with both Kobe and Duncan. Every one of them said it was Kobe and said it wasn't even up for discussion (and they all also agreed that Duncan is probably best PF of all time).