Neptune
Hall of Fame
The most dominant tennis player in his respective era is Roger Federer.
From 2004 - 2009, prime/peak Federer amazes us by winning a staggering 14 out of 24 slams !
He made 20 slam final appearances:
reaches 10 consecutive finals
reaches 4 finals in a season 3 times
won 3 out of 4 slams in a season 3 times
reaches 23 out of 24 slam semifinals
50 single titles
He accumulated 240 weeks at the top of the ATP rankings including an astonishing 237 consecutive weeks.
5 out of 6 years he ended the YE #1.
Prime Federer's dominance and consistency is off the charts !
Now giving up HC comparison which is this thread all about?

BTW, dominance and consistency without considering opposition strength does not mean much.