Hannekes Boom is one of the nicest waterfront café in Amsterdam to have a beer when it's sunny. Close to Central Station, the place isn't crowded by tourists, but you need to be there early to get a seat.
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!