9) Mateo Kovacic to Real Madrid (£26million)
Outside of the Premier League for this one as Real Madrid coughed up around £26million in order to sign Inter Milan midfielder Mateo Kovacic.
The Croatian international was strongly linked with a move to the Premier League, with Liverpool interested in signing him as a replacement for Steven Gerrard, but eventually the midfielder chose the Bernabeu.
The 21-year-old is predicted a massive future after shining at the San Siro, but with a wealth of options at Madrid already in his position, he could find it hard to break into the first-team on a regular basis.