There are a ton of great places to go in Belgium, it depends how much travel time you'll have, etc etc. If you're going to have a car and a little bit of time, one thing you can do is choose a beer (a trappist ale of course!) that you like once you're in the country, and then look up the Monastery where it is brewed! I was there for a year as an exchange student and I would have liked to go to Chimay but I never got the opportunity, however we did get the chance to visit others.
When in Brussels its a no brainier to hit Delirium, its right down in the tourist area near the grand place. I believe La Mort Subite is right near there too... In Brussels, instead of hitting the expensive bottle shops go a few streets away from the tourist area and go to a grocery store, there is a Super GB and a Delhaize on Rue du Marche aux Poulets that have excellent selection! Plus (this is a little random) if you go into the Super GB (Google maps says its a Carrefour now) and take the parking elevators up, you can get onto the rooftop where you have an excellent view of the city. On clear days you can see all the way out to the Atomium! We called this the GB rooftop, and would drink up there until security kicked us off (which rarely happened) its a local student and exchange student secret!
