#3 Eric Cantona
King Eric is probably best known for his kung fu kick on a Crystal Palace fan in 1995, but there was so much more that brought to the pitch.
Widely regarded as one of the best French forwards of all time, he signed for United from Leeds in 1992 for £1.2 million. Although he spent only 5 seasons at Old Trafford, his aggression and passion quickly came to signify Ferguson's reign in Manchester.
Cantona was a unique combination of strength, power, pace and technical brilliance. Sir Alex paired him with Mark Hughes after he arrived, and he almost single-handedly carried them to the Scot's first league title at Old Trafford.
In the '96 FA Cup final against fierce rivals Liverpool, his goal in the dying minutes of the game helped United record a 1-0 victory, as Cantona (who was stand-in captain for Steve Bruce), became the first player outside of Britain and Ireland to win the tournament as a captain.
After Bruce left in 1996, he was named club captain. His 11 league goals in 36 appearances helped them retain the title, but in a move that shocked the entire footballing world, he announced his retirement from football at the age of just 30.
His short-lived career also meant that he had only 45 caps for France, but a combination of his incredible talents and his constant dallying with controversy meant that he was one of the inaugural inductees of the English Football Hall of Fame.
Like Robson, Cantona's playing career under Ferguson was short-lived, but he's still undoubtedly one of the very best.