Nagato is the one obviously, he is an Uzumaki therefore his force of life allows him to draw the best out of the rennigan... Edo Madara cannot, I repeat cannot use all the technique but Nagato could use the dragon, rinne tensei, chibaku tensei, Shinrai tensei, all the summonings, the robot part, he showed them how to use it on dead corpses by transmitting chakra and connecting all the eyes as one via all d other parts.
If Nagato and his 6 parts happens to have a rennigan fight against Madara just based on rennigan, Nagato will win.... He can revive any of his parts, his seventh part can use the dragon technique to scoop madara's life away in just one touch, which madara cannot use if not he would have used it against the alliance shinobi a long time ago or he would have use shinra tensei on them or even the summonings.