John McEnroe reach the #1 spot in the world 13 different times. John McEnroe is also the only player to be ranked #1 in the world in singles and in doubles simultaneously.
From 1973 – 1988 Jimmy Connors managed to stay in the top 10 for 788 consecutive weeks. He also has the record for the most years where his year-end ranking was in the top 3 – 12 years in a row starting in 1973. In addition, there was the most years in the top 5 – again starting in 1973 for 14 years consecutively except for the year ending 1986 rankings.
Jimmy Connors also shares the most year-end top 10 rankings with Andre Agassi – 16 years. Connors was 16 years in a row, again starting in 1973 – which is the record for consecutive year-end top 10 rankings. Agassi was top 10 year-end in 1988-1992, 1994-1996 and 1998-2005. From 1987-2005 Andre Agassi was ranked in the top 25 at the end of the year – a record 18 times in a row.
At 17 years, 11 days old, Aaron Krickstein became the youngest male player ever to be ranked in the top 10 (actually he was 9th). he had also been the youngest player in the top 100 which he reached when he was 16 years, 4 months old.
For more details see the slide show at Bleacher Report – CLICK HERE