Brugge is a beautiful city. Ghent is also a nice trip, but if you have to choose between the two, go to Brugge for a side trip. Belgium is one of my favorite European countries. The EU complex in Brussels is also quite impressive if you're looking to see something a bit more modern. The European Parliament building is pretty neat inside and outside. There is a lot of construction going on over there. You could also go to Amsterdam for the day too if you're looking for a little bit more of a trip. Enjoy!