Jean Bouin versus Hannes Kolehaimen 1912 Olympic 5000m final
Paavo Nurmi versus Wille Ritola 1924 Olympic 5000m final
Jack Lovelock versus the rest of the field 1936 1500m final
Gundar Hagg versus Arne Anderson 1944 Malmo mile
Emil Zatopek versus Gaston Reiff 1948 Olympic 5000m final
Emil Zatopek versus rest of the field 1952 Olympic final
Roger Bannister versus John Landy 1954 Empire games mile
Peter Snell versus Roger Moens 1960 800m Olympic final
Herb Elliott versus rest of the field 1960 Olympic 1500m final
Billy Mills versus Ron Clarke versus Mohammed Gammoudi 1964 Olympic 10000m final
Juha Vaatainen verus Jurgen Hasse 1971 European Champs 10000m final
Prefontaine versus George Young US 5000m 1972 Olympic trials final
Dave Wottle versus rest of field 1972 Olympic 800m final
Lasse Viren versus Prefontaine et al 1972 Olympic 5000m final
Filbert Bayi versus John Walker et al 1974 Commonwealth games 1500m final
Lasse Viren versus rest of field 1976 Olympic 5000m final
Take your pic. It was harder to get excited about perfomances after the early to mid 70s because of drugs, professionalism, dodgy agents, corruption in the governing bodies etc ...