The Emilia-Romagna Grand Prix is taking place against a backdrop of severe doubts over Imola’s Formula One future. The deaths of Roland Ratzenberger and Ayrton Senna at the 1994 San Marino Grand Prix remain etched on F1’s psyche but the demanding Autodromo Enzo e Dino Ferrari has been the scene of some of the sport’s most-compelling races. Here are three of the best: