Roy Keane

There's no messing with Roy Keane. The Irish bruiser is simply one of the mightiest, most formidable talents to ever grace the Premier League, leaving a void in the middle of the Old Trafford midfield that many feel Manchester United have still to really plug since his departure in 2006. It was Keane who gave Fergie's United side the discipline needed to win seven Premier League titles between 1993-94 and 2002-03, not to mention a famous UEFA Champions League victory in 1999. A tough-tackling pass master, not afraid to speak his mind, Keane is now Republic of Ireland assistant manager but remains a hero among the Reds' support.