Lucas Romero, Martin Odegaard, Youri Tielemens, Mateo Kovacic, Paul Pogba (<< this is the most expensive player - and not really the best either)
For me... Lucas Romero is the best of them all, I feel Pogba is better but he isn't as consistent as Romero, Romero is valued at £45m, Pogba at something like £56. Romero has an average rating of ~8.2 for me while Pogba is down at 7.8. Odegaard is to young, he's still 19 but he's developed extremely well, received bids in excess of £30m from Juventus, Barcelona, etc but I rejected them all - he's starting to break into my first team, as for Youri Tielemens, he moved to Arsenal from ANderlect in my save, he's developed very well there but their manager (Michel - from Spain) favours Ramsey and Wilshere who aren't as technically gifted as Youri but... more complete central midfielders.