In 1921 Babe Ruth hit 59 home runs in 152 games played.
In 1927 Babe Ruth hit 60 home runs in 151 games played.
As of 19 Sep 1999:
In 1999 Sammy Sosa has hit 59 home runs in 140 games played so far.
In 1999 Mark McGuire has hit 54 home runs in 135 games played so far.
The games played are the games each man has played in not the numbers of games the teams played or has played so far.