Curry and it's not even close. The reason is that every PG listed is a shooter, not just a distributor. Paul would be the most pure form of a PG that does both well, but since the PG is the 1st option to shoot the ball (based on the fact they have the ball at the beginning of most possessions) the better they shoot the better they are. None of those shoot better than Curry. Any of those would run circles around anything on the Spurs roster with a "PG" after their name.
Curry is a gifted passer but he's too free to turn the ball over without extreme consequence because his team is good enough to compensate. So he'll sling the ball across the court and turn it over more than he should, but he has the ability to not do that and still be effective as long as he doesn't try to do too much. With KD on the floor as well, his passing is even more important.
John Wall is highly underrated. I'd like to see him on a team with a legit chance at winning.