10: Marquinhos to Paris Saint-Germain
Beginning our countdown we start with the mega-money move that took the relatively obscure Marquinhos from Roma to Paris Saint-Germain.
A deal that consisted of a talented young star moving to a club on the up, with a view to a long-term future in Ligue 1; it all seems all right doesn't it?
Then when you factor in that cost of the move, €31.4million, and the little experience of the player in question you can begin to question PSG's motives. This year he's struggled to break up the duopoly of Alex and Thiago Silva... surely the French champions would have been better served buying someone who cost far less?