#1 Spygate Controversy
The Spygate controversy is probably the biggest scandal in the history of Formula 1, which primarily involved Ferrari and McLaren, concerning McLaren's possession of Ferrari information illegally.
Interestingly, the whole scandal came into light after the 2007 Hungarian Grand Prix fallout between Fernando Alonso and Lewis Hamilton.
Alonso's heated argument with McLaren boss Ron Dennis in the morning of the Hungarian Grand Prix blew the whole issue out of proportion, while also playing a part in bringing new evidence into the light, which ultimately reopened the FIA investigation into the matter that was closed earlier.
McLaren was fined $100 million for the possession of confidential Ferrari information illegally, which all came to light after the cooperation of McLaren's drivers. Furthermore, the team was disqualified from the 2007 constructors championship. However, both Alonso and Hamilton were not penalised for the incident.