Well I may not be a native, but I just got back from Belgium and I can tell you it's a very lovely place. Of course in Brussels the most important thing is to see the Grand Place at night as it's very beautiful. If you appreciate music at all, I strongly recommend visiting the Musical Instrument Museum; it's both a visual and auditory experience unlike anything I've been to. When it comes to pubs, I would suggest trying L'Mort Subite (Sudden Death). I promise you won't experience sudden death, though I'm sure you'd agree it's quite appropriate for a Downer to visit.

Anyways, it's a really nice little place with good drinks and a relaxed atmosphere. Now if you go to Belgium, I recommend you also visit Bruges for a day. It's a beautiful place without the big city feeling, though it is pretty touristy (it wasn't so much when I went, but that's because it's out-of-season). If you do go there, there's a restaurant called De Hobbit and a pub called Bistro Tolkien as I've mentioned in another thread...
I'd also like to thank everyone for all the advice. Studying abroad in Europe, I'm planning to do a lot of traveling myself, and I'm finding some of this quite helpful.

Perhaps I should take advantage of this thread and list where I'm going too...