Easy.
01. Mac 1984
02. Djoker 2011
03. Fed 2006
I am a big fan of Novak, but lets be real, in 2015 Nadal was out, Federer was 34 and most important of all Stan did beat Novak comprehensively in the final, for a guy who is supposedly at the zenith of his powers this doesn't look well to lose to Stan, same as Federer 05, looked like he was at his zenith but Safin beat him fair and square, so these sorta years where somebody beats you with a supreme performance makes it tough for your peak to be actually be considered the ceiling of Tennis. 1984, 06 and 11 are savage seasons, especially 1984 which is probably the greatest season ever.