Niki Lauda, probably my favorite Formula 1 champion, mostly for this story :
During the 1976 German Grand Prix his Ferrari burst into flames and he came close to death after inhaling toxic fumes and suffering severe burns. He lost most of his right ear, eyelids and facial hair. However, he came back only six weeks after his accident to defend his title, the face still covered in blood-soaked bandages, unable to blink. He was still performing, finishing fourth in the Italian GP for his comeback.