Our first Netherlands experience was Amsterdam in 2015 - an almost surreal city. It combines history and art with a culture unlike any other.
We thoroughly appreciated a tour through the apartment that Ann Frank and family stowed away in during WW2. It was a mute tour, where the museum asked that all visitors be quiet until the end. Without sound, you could "feel" every room in that apartment. It was an extremely powerful experience.
We also enjoyed exploring the city and seeing it's cultural differences first hand (different for us that is). There were college students filling restaurants with thick smoke, legal prostitutes pedaling their wares in open windows, and even a small fully devoted "condom museum". There really is nothing like Amsterdam, or at least that we have come across in our travels thus far.