I have been fortunate enough to live in The Netherlands for over a year at one point in my life and I know Amsterdam Schiphol (AMS) very well...I recently had the chance to visit it again after a long absence...and I still think is one of the best airports in the World, and possibly the best in Europe for plane spotters!
Is not only modern, clean, convenient and perfectly connected with regular and frequent ground transportation (it sits on a main railway trunk line), it's got great shopping, restaurants, even an art museum!...it is the small details that end up delighting the aviation enthusiast and planespotter! Here is a sample:
Aviation shop: all sort of memorabilia, aircraft models and other aviation-related stuff can be bought here. the shop is conveniently shaped as a KLM aircraft!
While walking along Schiphol's corridors you will find these indicators whose aim is to help the public recognise the different types of airplanes that are visible across the glass
Panoramic Terrace, although this photo contains only KLM aircraft, a very diverse mix of airlines from all over the World fly to AMS, which makes for a very interesting plane spotting opportunity!
The panoramic terrace is great for plane spotting!