For me, Djokovic at his best is better than Federer and Nadal at their best.
It’s a tricky one, Nadal has remained at the top and won so much despite having so many injuries, I think if you take away the injuries and Nadal has the consistency as Federer with going long periods of time without injury, then he would be outright ahead of everyone to have played the game.
Federer has been consistent for such a long period of his career and every time he looked to be winding down he’d show he’s still got in him. The last few years though he’s had some really sketchy defeats that make you think that there really isn’t much left in him now.
Djokovic I think was slightly overshadowed by the other 2, it wasn’t really until 7/8 years ago(?) when he beat Nadal in the Wimbledon final that he really came into his own and started to show he means serious business. He was unlucky with injuries for about a year not long ago, the guy couldn’t seem to catch a break and I didn’t think he’d ever come back from that and get to the level he was at, since he’s been back though he’s been on a mission, he’s played better than ever IMO and since Wimbledon he’s stepped it up again.
There’s so little in them and being a Nadal fan I’d probably be a bit bias towards him because he’s playing some great tennis and adjusting his game really well to carry on playing. But, I think Djokovic will go on to be ahead of both Nadal and Federer, you look at the latter two and you can see plenty more injuries coming their way, where as I think Djokovic will be able to maintain this level of performance for longer and find it much easier to do so.
For me, whoever wins the Oz will edge ahead of the other at this moment in time but I’d say they are now both well ahead of what Federer has left him him.