Never been to Brussels but heard its not great. Ghent and Brugge are worth seeing and only a short train journey away.
I'm a massive Belgium beer fan, a few I'd recommend are:
-De Koninck Triple d'Anvers
-Chimay White
-Verboden vrucht
-Bruge Zot Blond
-Triple LeFort
-Tripel de Garre
-Carolus...