Juan Manuel Fangio and Ayrton Senna voted as F1 's best by motorsport greats . Argentine Fangio won four world championships with five different teams . Brazil 's Senna won five drivers ' titles in the late 1980s and early 1990s . Blog : Alonso , Vettel on track for greatness ? Senna was killed during a crash at the Imola circuit in early 1990s .
Juan Manuel Fangio and Ayrton Senna voted as F1 's best by motorsport greats . Argentine Fangio won four world championships with five different teams . Brazil 's Senna won five drivers ' titles in the late 1980s and early 1990s . Senna was killed during a crash at the Imola circuit in early 1990s .