Amsterdam, Berlin or Brussels?
 

My daughter is studying abroad in Copenhagen and is running out of weekends that she can travel. If she can only choose 1 of these cities, which one would you do?

Of the three I've been to Amsterdam and Brussels, and if the choice was between those two, I'd definitely pick Amsterdam. I really enjoyed both cities, but Amsterdam is a place I could see returning to again and again. Plus there seemed to be more in Amsterdam aimed at young adults.

From a pragmatic point of view, Berlin is probably the most affordable capital. You can find lots of hotel bargains at hrs.com, food / street food is probably only a fraction of what she is used in Denmark -- esp. the ubiquitous box of chinese noodles for €1.50 :-)
Berlin is much larger than Amsterdam or Brussels, and will definetely keep a young adult entertained for a weekend. It's one of Europe's hotspots for clubbing, going out, pubs etc.

Another vote for Berlin. Plenty to suit her interests whether nightlife, museums, history, architecture, food, etc.

Amsterdam second, Brussels third.

Thanks for the replies. I, too, was thinking Berlin over Amsterdam and Brussels. I was last in Berlin right before the wall came down so I'd love to see the change.