If we're speaking strictly at playing the PG position, Paul and Nash are probably the best I've ever seen(I only saw post-prime Stockton and didn't see Magic), but Curry is easily better as a player IMO..
Being able to dominate a game without needing to dominate the ball makes him more unique and versatile than somebody like CP3 that always dominates the ball, tbh..
Tom Haberstroh(I think it was him) had an article/study last year, even prior to Curry's MVP season, where they discovered that Curry has by far the highest "gravitational pull" in the NBA for opposing defenses, meaning that he creates more opportunities for his teammates than any player in the league, even without having the ball in his hands..
He's a historically great player for his position IMO, but I don't think people realize it due to the skewed perception because he's small and he's a shooter..