Ali Saidi Sief, Algerian (anti) hero, who crossed the line with Nandrolone at W.C. Edmonton, 2001. 2nd in 5000 behind (clean) Richard Limo. That was a super fast race with Limo in 13:00, Sief 13:02, and even Spanish warrior, Alberto Garcia 13:06.
The tragedy of all this and many other cases is that these athletes who broke the rules were still talented and could have reached super high levels without doing these things but impatience and greed pushed them to cross the line.