We pick out 10 contenders for the men's title and some interesting outsiders at Wimbledon, which begins on Monday.
It was at Wimbledon 12 months ago that Djokovic ended what for him was a grand slam drought of just over two years and he did not look back, winning the US Open and Australian Open to return to the top of the world rankings. He has won four times at SW19 and will again be the player to beat.
After Rafael Nadal's 12th French Open crown, can Federer make it nine at Wimbledon? He surprisingly exited at the quarter-final stage last year, despite having match points in his clash with Kevin Anderson. Federer's results in the grand slams are on the slide, having not made a final since the Australian Open last year, but even at 37, there are few players who can match him on the grass.
It will be another year of heading to Wimbledon on the back of a French Open success for the Spaniard after his 12th Roland Garros triumph earlier this month. The world number two's knees have not been too keen on the transition from clay to grass in recent years, but his run to the semi-final last year - where he lost an epic five-set thriller with Djokovic - was his best performance at the All England Club since 2011.
Tsitsipas has had a breakthrough 12 months which has seen him win three ATP Tour titles and reach the semi-finals of the Australian Open. The Greek defeated Federer in Melbourne, which proved he is capable of matching the world's best, and is now a firm fixture in the top 10. At 20 his best years are ahead of him, but his highly entertaining style of play will have fans on his side and he will be targeting a run deep into the second week.
The 22-year-old German has been a constant source of frustration for those wanting to see the next generation finally try and topple the big three. Away from the grand slams Zverev is a match for anyone and has won some of the biggest titles, but he has struggled to transfer that into the best-of-five matches, as yet unable to get beyond the quarter-finals. But he has the undoubted talent that makes it impossible to think some success is not too far away.
The South African cannot be ignored, owing to his run to last year's final. He disposed of Federer in the quarter-finals and then beat John Isner in a marathon semi-final where the deciding set ended 26-24 in his favour. His massive serve and powerful groundstrokes make him a threat against anyone at SW19, as a victory over world number one Djokovic in 2016 testifies.
The Austrian is the next-gen player who has got closer than anyone to breaking the stranglehold of the big three with back-to-back French Open final appearances. At 25, he will know that his time to deliver is coming and will hope that the success on the clay will give him confidence on other surfaces. A fourth-round appearance in 2017 is his best effort at Wimbledon but a picturebook single-hand backhand and speed around the court make him a threat.
Still a baby of the game, at 18 the Canadian is the youngest member of the top 100 and he is only heading one way. His early-season results have catapulted him up the rankings, having made three tour finals and enjoyed deep runs at Indian Wells and Miami. He reached the quarter-finals of the junior event at Wimbledon in 2016 and has the athleticism to cause anyone trouble.
The Russian proved his potential when he beat Djokovic to claim the Paris Masters last autumn in what remains his biggest career win. With a monster forehand and pinpoint serving, Khachanov will be one of the mainstays at the top of the game for the next decade or so. He will be keen to build on his run to the last eight in Paris last month, which is his best grand-slam performance to date.
A player of eye-catching ability, Shapovalov's undoubted potential has yet to be realised on the biggest stage, having failed to make it into the second week in any of his last six grand slams. The 20-year-old bowed out in the second round of Wimbledon last year, but his junior title there in 2016 means grass is a surface he enjoys playing on and any of the big names will be keen to avoid him in the draw.