I spent time in Brussels and liked it a lot.
Here are two recommendations I have:
Wittamer on the Grand Sablom for some expensive chocolates. Get the pineapple one. It's magical.
There's a restaurant Les Brassins at 36, rue Keyenveld. It was recommended by the NYTimes in their 36 hours of Brussels column and we really liked it. Probably nothing terribly special in terms of haute cuisine, but it was good and the prices were good. http://travel.nytimes.com/2007/07/08...l/08hours.html
It's kind of hard to find to mark it on a map first.
I would also recommend taking a tour of the great Art Nouveau architecture that Brussels has to offer. Victor Horta and other architects really did a beautiful job. We did a bus tour through a company the name of which I can't possibly remember. Well worth it. And surely to put Brussels ahead of Berlin aesthetically. (sp?)
And there's the new Magritte museum which is supposed to be great.