3. David Luiz – Benfica to Chelsea (£26.5m)
After weeks of rumours and speculation linking the Brazilian centre-back with Chelsea, Luiz made the move on the winter deadline day of 2011.
He divided opinion between fans during his time at the club and was often criticised for his defensive abilities, with experts suggesting his attributes would be better suited to a midfield role.
A venomous free-kick and a leap that could contend with some of the Olympic high-jumpers, Luiz was always in with a chance of scoring goals. The defender commanded set-pieces in his three-and-a-half-years at the club, and struck 12 times in the process, before moving to French giants PSG for a staggering £40 million.