Coe in 1980 Moscow 800 final -- hands down, no argument. He was by far the best two-lap runner in the world and all he had to do was get out front and run and nobody could have stayed with him. Instead, he was mostly in 6th place and a few lanes too wide on the back straightaway of the first lap. And he never really did get going until it was way too late and he didn't show much then. Most likely it was nerves. He was then hounded by the media, they followed him in cars on his distance runs, and the British press said he was done, career over. I doubt anybody ever raced with as much pressure on him as Coe did several days later in the 1,500 final. He ran great. So perhaps the worst running in an Olympic middle distance final and the best running in an Olympic middle distance final were run by the same man, just several days apart. Right before the Olympics if somevody had said Steve Ovett would win the 800 and Seb Coe the 1,500, one would have thought that was impossible. It was impossible. But it happened anyway.
On a side note, I suspect neither Brit would have won either race had Ivo Van Damme not been killed in an auto accident. He was a double silver medal winner in Montreal with Ovett in only one final and Coe not on the British team. As Americans, we tend to think of how great a loss the death of Prefontaine was. Van Damme was by far a greater talent than Pre.
Strangely, Bronislaw Malinowski, who won the steeple in Moscow, overcoming a 40-meter deficit on the final lap, was also killed in an auto accident. He overtook Filbert Bayi on that last lap in one of the more exciting Olympic finishes ever -- at least until the 10,000 in Sydney.