#2 Cristiano Ronaldo
Arguably one of the two best players to ever grace a football pitch along with Lionel Messi, Cristiano Ronaldo truly achieved greatness at Real Madrid and with Portugal but he was set on the path to all-time greatness by Manchester United and Sir Alex Ferguson.
Ronaldo was first noticed by United in a pre-season friendly, when he was playing for his boyhood club, Sporting CP. As a 17-year-old, Ronaldo toyed with the likes of Wes Brown and John O'Shea, both who were, by that time, established Premier League defenders. The story goes that after that game, all the United players begged their manager to sign the teenager, which he did, in 2003, when Ronaldo was just 18-years-old.
Ronaldo spent six years in Manchester, which he has often described as some of the best years of his life, also saying in interviews that Sir Alex was like a father to him, especially after the death of his real father, early on in his United career. Ronaldo scored 118 goals in 292 games in England, including 42 in the 2007/08 season, which ended with United lifting the Premier League and UEFA Champions League.
For United fans of a certain age, Ronaldo is the reason their loyalties lean towards the Red Devils and he has provided them with some of the greatest footballing memories of their lives.