25 players
As many as the players can hit. There is no limit.
104
25
2 players hit 40 or more home runs in 2008, both from the National League. R. Howard(47), and A. Dunn (40)
Nobody did
Every Single MLB Player Has Hit A Homerun.
All of them.
zero
1500
As of 2009, 125 players have hit 300 or more career homer runs in the Major leagues..
122 different players have had a total of 295 40-HR seasons.