Canadian sprinter Ben Johnson
No one was faster than Johnson. The Jamaican-born Canadian sprinter set the world record for the 100-m dash at the 1987 World Championships and then broke it at the 1988 Summer Olympics, winning the gold. But then he was brought down by — you guessed it — steroids. Johnson tested positive for Stanozolol, a testosterone-based steroid often used in bodybuilding. He was stripped of his medal as well as his two world records. Johnson made a brief comeback but was found guilty of doping in 1993 and again in 1999 — this time, for a banned diuretic used to mask other drugs. That same year, Libyan leader Muammar Gaddafi hired Johnson to teach his son soccer.