Brussels has remarkable Art Nouveau sites: the Victor Horta museum and the music museum in a converted department store building are two. If you discover that you have seen enough of Brussels, you can always take a day trip to Bruges or Ghent. The same is true of Amsterdam from which one can easily reach places of interest in the Netherlands, all via public transportation.

http://www.flickr.com/photos/mksfca/sets/72157622960216715/

Contrary to a lot of opinion we really enjoyed Brussels. We spent four nights there this March. I'm attaching the link to my trip report—if you're interested you can check it out.

http://www.fodors.com/community/europe/backwards-trip-reportfour-nights-in-beautiful-brussels.cfm

We took a 2 week trip to Brussels and Amsterdam a few years ago and had a wonderful time.

We spent 4 nights in Brussels, 3 in Bruges, and 5 in Amsterdam - then a final night in Brussels before flying home.

We liked Brussels a lot too and thought that 4 nights was just about right. We had planned to do a day trip or two, but opted not to because we were enjoying Brussels so much. If you want to do day trips, I would recommend another night at least for Brussels.

Bruges was a nice small-town break. In retro-spect it seems that 3 nights there was probably 1 night too much, but there are some good day trips from Bruges that you could take though, which would make 3 nights a good idea.

The 5 nights in Amsterdam seemed about right - of course we could have spent longer and done more day trips, but we thought that 5 nights was good. We took a day trip to Delft from Amsterdam, which we really enjoyed.

Here is a link to my report:

http://www.fodors.com/community/europe/belgium-and-the-netherlands-trip-report.cfm

www.eurocheapo.com/amsterdam my fav consider a houseboat
www.eurocheapo.com/brussels bigger city crowded
Bruges the Venice of the north my fav...

Have fun!

I prefer Antwerp over Brussels. From Amsterdam there are a number of possible day trips, including the Zaanse Schans, Haarlem, Delft, and many others to get you out of the big city.

Thank you all- this is a great help. One more question -what is the best way to get from Brussels to Amsterdam.

Check out Thalys train as the best way to get from Brussels to Amsterdam. If you buy your tickets 90 days in advance, it is about 26 Euro per ticket. Thalys is a TGV-like high-speed train. it takes about 2 hours from Brussels to Amsterdam. I took Thalys from Brussels to Paris and it was a fabulous experience. Even though the train travels about 100 to 300 miles an hour, you can still see the scenery.

We recently spent 10 1/2 days based in Brussels seeing that city and taking day trips to Mechelen, Antwerp, Leuven, Tournai,Villers la Ville and Tervuren. We had visited Brugge and Ghent on earlier trips. My trip report is about half finished and I would be happy to answer questions about the day trip locations I have not described yet.