Well, being from portugal, i will reply first about what I know best. I would have to say that in my coutry the best wonder kids are iturbe, james rodriguez, christian atsu (!) and kelvin and of course Tomás Podstawski from FCPorto; Andre Martins from Sporting CP; Sancidino Silva from SLBenfica.
Outside my coutry I would consider the mexicans Carlos Fierro and Erick Torres, as well as Marco Fabian. The Italian Marco Verratti, the english Sterling and Chamberlain, the argentian Ocampos and Manuel Lanzini, the brasilians Paulinho and Casemiro and the German Emre Can.