Nemanja Vidic transformed Manchester United as a football club when he arrived in January, 2006 with left-back Patty Evra.
Sir Alex Ferguson had long sought for a suitable partner for Rio Ferdinand without avail. Wes Brown, O'Shea, Johnsen, and Silvestre were often employed without great effect. Vidic arrived and the rest is history.
Three straight Premier League crowns and a European Cup later, the Serbian nicknamed "Monster" is the best central defender in the world.
In the air, Vida is absurdly dominant. On the floor he either tackles you or fouls you; that's sound defense, in'it?
He is a true competitor, enjoying putting his head right where it hurts against the world's best. He has constantly got the better of Didier Drogba—Fernando Torres, not so much.
Going forward, he is still growing, but has shown to be practicing his footwork, visibly improving with each foot in the last year and half, both in turning and passing.
Despite only being at United for four years of the decade, Vidic trumps all other United defenders because of the immediate effect he had on the side.
Without Vidic and his comrades at the back, United's attackers wouldn't have had license to get forward to win the recent glut of trophies. His partnership with Ferdinand is, at times, the best in the world, mainly depending on the variable form of the Englishman.
When United famously went 14 games unbeaten in 2008 and 2009, Vidic was the only defender omnipresent in the lineup. Though Van der Sar took home the accolades for the feat, the credit belongs to the fan favorite Serb.
He has been named in the PFA Team of the Year for three seasons on the trot.
If United can rebuff Barcelona's interest, Vida should continue to be the prime ingredient for United's success in years to come, and should end up the permanent captain once Neville retires.