I prefer Feds style of play, effortless, moves like a dancer on the court, so elegant. He is an all time great, possibly the greatest.
Rafa as BT pointed out is mentally tougher. A league of his own. He is also the premier athlete on the court, or was. Why I always root for Rafa: his personality, that humbleness, his playing each point as if it's his last. He is the perennial underdog (apart from clay) champion who doesn't whine. He has won all the majors, he has done it all.
Wonder if Joker or Andy will go back to dominating. Or will Roger and Rafa find a second wind.