Arnold Schwartzenegger: Best all time ambassador.
Eugene Sandow: Basically invented the sport.
Lee Labrada: Proved the small guys could compete with the monsters. Amazing symetry.
Lee Haney: Gave bodybuilding a huge shot in the arm (no pun) by surpasssing Arnold's Mr. O titles.
Dorian Yates...
IMO, no such thing as a "safe" drug. Your best bet is to do extensive reasearch and weigh the reward to risk ratio of any drug / supplement. Any drug in excess can have serious consequenses. Even vitamin C can be harmful and Tylenol can destroy your liver if abused.