Unfortunately it’s not in Amsterdam but De Pont, museum of contemporary art is worth the 1,5 hour trip with the train. The building itself is beautiful, it’s a former wool mill but also there collection is worth seeing!
Almost every underground station in Amsterdam has a fascinating story behind it. My favourite one is metro station ‘Weesperplein,’ because it has a hidden station underneath the actual station that was meant for the 'Singellijn.' However, that line was never build and the second station remained useless. Besides that the hidden station was also equipped to serve as a shelter during the cold war. The large doors that were meant to hermetically close the building are still visible at both ends of the platform. Other small details, like the panels in the ceiling than can be used as tables when turned around, are also silent references to the building’s former use.
Since I’m a graphic designer I'm obviously into books and my favourite bookstore in Amsterdam is Boekie Woekie. This small shop is located in the Nine Streets and they sell nice and special publications that are often hard to find because they are self published or published by small press publishers. If you are into graphic design you should really check it out.
Candles, incense and fragrance oil to lighten up your place, this place carries tons of it. You might be greeted by the slightly unusual owner, sitting behind the counter smoking a cigarette. It's an authentic little store.