There is no doubt that Federer is the greatest of all time however we are seeing that Djokovic isn't very far behind him and I even rank Djokovic ahead of Nadal because Djokovic has won more Grand Slams on different surfaces where as Nadal has won all he's Grand Slams mostly on clay which in my opinion isn't a very good record. Yes he is the king of clay but it would look better if he won more Grand Slams on other surfaces like Djokovic and Federer.
If Djokovic continue his run and eventually past Federer with the most number of wins in a Grand Slam then no doubt we will have a discussions as to who is the GOAT of this general and others might consider him ahead of Federer if we are going to base on that criteria.
The strengths of both player in any surface is also a indication how great they really are as compare to Nadal's amazing run on clay specially on French open. But currently, for me it is still Federer, at the top of my list.
@Royse777 - Don't you worry mate, I'm sure you will recover that 0.05BTC you have lost in tennis.
Yes I still rate Federer at the top and it is hard to compare the great players. There is one thing that for me outshines Federer when it comes to comparing him with Djokovic and that is that Djokovic has done this in an era where there have been the best players we have seen and he has beaten them all. Just think back to when Federer and Nadal were winning all their Grand Slams, they didn't really have much competition where as Djokovic has had to play and beat arguably the two best players ever and not once but on a number of occasions. We can also put Murray into the mix up there with Federer and Nadal so when we look at it, Djokovic has played and won in an era that is a lot tougher then when Federer and Nadal started to win their Grand Slams.
Don't get me wrong though, I still think Federer is one of the greatest players ever but when you look at Djokovic record and who he has beaten it just looks a lot better.