10. Edwin van der Sar
When Fabian Barthez left back in 1999, Ferguson was left looking for a replacement. And after failed attempts with other keepers, he turned his attention to a 34-year-old Dutchman who was playing for Fulham. Fergie signed him for 2-million and was one of the smartest buys. van der Sar went on to play 266 games for United, and won four Premier League titles, two FA Cups, and One Champions League. During his six-year career for United he recorded 72 clean sheets and recorded 126 wins during that time.