#1 Neymar Jr.

Brazil were humbled by Belgium in Russia and were knocked out at the quarter-final stage. Neymar Jr. made the headlines for the wrong reasons like simulation and the like instead of his undeniable talents on the ball.
He won the double with PSG last season but failed to win the elusive Champions League for the French side. Reports have been coming in all season about the Brazilian not quite enjoying life in Paris and is seeking a return to Spain, most likely with Real Madrid.
PSG lured Neymar away from Barcelona for a record transfer deal worth €222 million last summer. He had been brilliant for PSG before leaving the game against Real Madrid in the Champions League injured. He hasn't played for the side since and only returned to action for Brazil in Russia.
Florentino Peres is reportedly obsessed with signing the most expensive player in football history and he remains a top priority for Los Blancos in the transfer window. Any move would involve having to top the fee that PSG paid to Barcelona and given the kind of money involved in football these days, who knows how much that could end up being?