Hoorn used to be an important harbour in the 17th ("golden") century.
http://www.hoorn.nl/main/index.html
It was the seat of the first multinational company in the world: the United East-Indies Company (VOC). The old center of town still breathes the ancient atmosphere with 17th century houses and cobblestone streets.
Alkmaar very much has the same feel, but it's a bit more crowded.
http://www.alkmaar.nl
And of course, there's the aforementioned Zaanse Schans: a village of rebuilt historical houses and windmills, where you can see cheese and wooden shoes being manufactured.
http://www.zaanseschans.nl/EN.html
Come to think of it, Showboat is only a few clicks away from the Zaanse Schans. ;-)
So much for the tourist info. I oughta charge money for this...