Just some nice addresses from someone who actually lives here. Varies from typical Belgian cuisine (yes, it exists!) to Italian and other Mediterranean cuisine to Asian and more exotic dishes.
Most restaurants will offer main courses for 8-15 EUR, while almost all of them offer cheap lunches (5-10 EUR) or interesting evening arrangements (15-30 EUR). All prices exclude drinks, but these aren't very expensive in Brussels!
Quick Tips:
Most dining places are ok, but a lot of the cheaper ones are really great. It's only a matter of knowing which oine falls in which category.
In addition, always follow the general rule: never eat in places where they display pictures of the food they are supposed to serve...
Best Way To Get Around:
Public transportation usually stops around 11pm-midnight, so the only solution is taxis (quite expensive: min. 15 EUR/ride), or to walk for as long as you stay in the city centre.