#1. Nemanja Vidic (Spartak Moscow to Manchester United, 2006)
Alongside Evra in 2006, Vidic was the other defensive signing Sir Alex indulged in. Though Manchester United were unable to catch the runaway Chelsea train that season, they unearthed a gem in Vidic.
For years, Vidic and Ferdinand formed a rock-solid partnership at the heart of Manchester United’s defence and led the club to unparalleled success.
While Vidic was at United, he won nearly every trophy on offer with the FA Cup being the only exception. To supplement his five Premier League titles, he won the FA Community Shield the same number of times, the League Cup on three occasions. However, his crowning glory was the victorious Champions League campaign in 2007-08.
A tough tackler by trade, Vidic was rarely out-muscled in a duel and was as difficult a defender to get around as any. Moreover, his infectious commitment led others around him to scale greater heights.
The January transfer window is a notoriously hard time to draft in world-beaters. Yet, Sir Alex managed to pull a rabbit out of his hat with Vidic.
For his time at the Theatre of Dreams, the Serbian would definitely go down as one of the greatest defenders to have ever plied his trade in the Premier League.
Thus, without a shadow of a doubt, he takes the top spot on our list.