It’s often said that men’s tennis is deeper and more competitive than it has ever been. And it’s true; the sport has never been played at a higher level. But over the last five years, it hasn’t been the excellence of the ATP as a whole that’s been most impressive. It has been the dominance of the top players despite that depth. Since 2006, we’ve seen three players—Roger Federer, Rafael Nadal and Novak Djokovic—put together seasons that rank among the most gloriously accomplished of the Open era.

Now that the third and perhaps finest of those seasons, Djokovic’s remarkable 2011, is complete, it seems like a good time to look back at where it—as well as Federer’s and Nadal’s best years—fits among the greatest single seasons of the Open era. There’s no right answer, and that’s what makes this parlor game so much fun. Here we present our countdown of the 10 best men’s seasons since the Open era began in 1968.

No. 6: Roger Federer, 2007

Oh so close again: That might be how Roger Federer felt at the end of yet another three-Slam season in 2007. For the second straight year, he finished one match short of winning a calendar-year Grand Slam; for the second straight year, that loss had come in four sets to Rafael Nadal in the French Open final. But Federer’s ’07 should be remembered for what he did win. That included his third Australian Open, a five-set revenge classic over Nadal for his fifth Wimbledon, a straight-set win over Novak Djokovic for his fourth U.S. Open, and his fourth ATP year-end championship. Federer had a higher winning percentage in 2004 and 2005, but Nadal had yet to reach his prime in those years. In ’07, Federer faced the toughest competition of his career, and he faced it down. Just as impressive, he was also coming off a career year the previous season, in which he had gone 92-5.

Check TENNIS.com each day for the next season on the list.

Originally published in the Jan/Feb 2012 issue of TENNIS.