Austin Crawford (Dallas, Texas) 50 meter dash world record: 4.98 second
Usain Bolt of Jamaica holds the men's world record in the 200 meter dash with a time of 19.19 seconds set at the 2009 World Championships in Berlin.
Usain Bolt holds the world record at 9.69 seconds for the 100 meter dash. Usain Bolt holds the world record at 19.30 seconds for the 200 meter dash. Michael Johnson holds the world record at 43.18 seconds for the 400 meter dash. So I would say Usain Bolt.
Florence Griffith-Joyner holds the women's world record in the 200 meter dash with a time of 21.34 seconds set at the 1988 Summer Olympics in Seoul.
The world record for the Woman's 50 Meter Dash (indoor) is set by Irina Privalova with a time of 5.96 seconds.
Usain Bolt, 9.58s