helterskelter
G.O.A.T.
In the Sampras-Kafelnikov era, aka Gold Era, you had to play all-time greats every round to win a slam. Kafelnikov won the same 3/5 Gold Slam that Djokovic has managed thus far, except the Kafelnikov 3/5 included the prestigious French.
Nishikori has the talent to beat everyone, but he is too kind to his fans and plays too much. Playing bunch of mickey mouse instead of spending quiet time at hospitals, ortho clinics, and rehabilitation resorts, even in the winter! Plus he refuses to bribe directors and gets stiffed on draws -- having to battle Djokovic in the USO semis instead of the easy breezy peasy cozy Federer for the Cilic fresh and rested like a spring cucumber for the final!
Talk about selective counting! Regardless of the status of the Olympic gold medal today, it was clearly and decisively below the year-end championships in prestige in 2000 (when Kafelnikov won Olympic gold). Also, winning an event counts, regardless of whether you've won it before or not. Even if I took your claim of which are the top five titles in tennis, Djokovic leads Kafelnikov 11-3 in them. Finally, here is a list of the all-time greats whom Kafelnikov beat in each round of his runs to win the three titles that you consider to be major. I've put in bold the ones whom I think might have a claim to be all-time greats. I tried to be generous.
- Galo Blanco, Thomas Johansson, Felix Mantilla, Francisco Clavet, Richard Krajicek, Pete Sampras, Michael Stich.
- Jonas Bjorkman, Jason Stoltenberg, Jim Courier, Andrei Pavel, Todd Martin, Tommy Haas, Thomas Enqvist.
- Juan Antonio Marin, Juan Ignacio Chela, Mark Philippoussis, Gustavo Kuerten, Arnaud Di Pasquale, Tommy Haas.