Rijksmuseum, Anne Frank House, canal tour by boat.
But mind you, A'dam centre is very very very very touristic, you won't see so much diversity and different nationalities anywhere in the world. Not in London, not in Paris, not in NYC, not in LA, not in Tokio. Not kidding
So a very busy place to be....
Every time we visit the centre my wife(latina) says to me I'm the only real dutch dutchman in Amsterdam
Cheers
Robin