I always thought the stadiums in Netherlands was some of the best:
Amsterdam Arena, Ajax Amsterdam:
De Kuip, Feyernoord:
The extended
Philips Stadium, PSV Eindhoven:
Germany has some great new ones and old ones too:
Allianz Arena, FC Bayern München and TSV 1860 München:
Munich Olympic Stadium:
The renovation and new building of portuguese stadiums has left some very interesting ones:
Estádio Municipal de Aveiro, S.C. Beira-Mar:
but this has to be the best looking stadium in Europe!
Estadio Municipal de Braga, Sporting Clube de Braga: