Amsterdam?
I wouldn't go there, but okay, if you insist.... ;) It is often packed with tourists, but of course, that is for a reason. Amsterdam has this unique ambiance, small authentic streets and canals with terraces, in which you can just sit and watch the world pass by.
Being a dutch guy myself, i visit Amsterdam every now and then. For example, to this Rembrandt exposition in the Rijksmuseum last year, in which i had to queue up in a waiting line of like 200 people. I took my smartphone and bought tickets, while standing in line, and i just could skip the line. And that's what made me setup this website....
So, to have more time for these beautiful cafe's and terraces: buy tickets in advance, here on this page.
Good travels to you all!
Roger