We should differentiate between the two surfaces. Agassi and Fed were the best on rebound ace. Djokovic has owned Plexicushion.
And yes, while Djokovic may have the more dominant run (of course and insane level Safin that would have beaten any version of Djokovic prevented Federer from 4 peating in Australia), Federer has been in 5 finals and 10 straight semis. His consistency cannot be overlooked. Novak will likely end up with more titles, but right now to say he's easily the best.... well that's just BS.