Many people say that standard Dutch is spoken in Haarlem, about 10 km west of Amsterdam. The original Amsterdam accent has some very specific peculiarities like a very strong S. Not really standard Dutch. Just like Agnes says the G in the Netherlands is strong and guttural. In Flanders though it is produced in a softer way with the tongue lifting in the middle and touching your palate. The R is usually a rolling R or Rhotic R and has no "curly tongue" like in English! The R can also be pronounced as a guttural R, more the case in Flanders because of the closer contact with French.