They have 4 fashion stores in Amsterdam with the biggest and coolest brands. I came across them while searching for Stone Island Clothing, they have the largest collection in Amsterdam. But not only Stone Island but they feature many other big brands like, Etro, Parajumpers, Hogan, Armani Jeans, 7 for al Mankind and many many more..
So if you are in the neighborhood and like to shop, go to Hartman en Hartman. You won't be disappointed.
Here is there website.