Alex, Sarah and I only had 2 and a half days in Brussels but luckily I knew a lot about it and the rest of the country before arriving by train from Paris. I knew it was the capital and that the Belgian people made great chocolate and waffles, they could speak France's language and had pretty well the same flag as Germany. There weren't any free tours so we would have to discover it as the new world explorers did, by looking around. And since none of us knew a word of flemish we stuck with french. The most impressive thing I found about this city is that everyone knew multiple languages. The man at the info booth who found us a good hotel when we arrived was fluent in 5 languages, our waiter who told us the water wasn't potable (it was) and served us bottled water instead also knew 5 languages and the manager of the chocolate shop we visited 3 times spoke 10. Yes, as in 9+1. This made me feel quite inadequate with my native english and decent french and inspired me to take on a third language seriously. Living in North America, spanish would be the obvious choice if I could only roll my "r"s....
Capital. We gave up looking for the parliment buildings but after visiting the EU headquarters and finding out that NATO was based out of there as well, Brussels is very much a capital city.
Chocolate and waffles. We visited the Chocopolis chocolate shop 3 times in 2 days and after Sarah ate more than her half of our delicious waffle a fight ensued.
Like France. Not only do they share the language but they both have impressive Arc de Triomphes. The french one is much older and grander but the belgian arc's surroundings compliment it far more than a busy car-packed roundabout does.
Like Germany. They do have the same flag while the belgian Arc de Triomphe and german Bandenburg Gate have the same quadriga statue up top. (Same = just short of identical)
-St-Michael and St-Gudula Cathedral: This church that I hadn't heard of was a great surprise. Just east of Grand Place, it had my favourite interior of any church I'd seen so far.
-Mannekin Pis: Europeans are strange. I didn't find this famous landmark of a boy urinating very interesting but because I was eating my undersized waffle half in the meantime, it wasn't a waste of time or money (its free). There's also a famous statue of a girl peeing which is unforturnately not next to a waffle shop.

-Palace of Justice: nice to walk past and behind it is a great view of the city.
Brussels is a great city to walk around, enjoy a musical flemish trio in a park or appreciate buildings built with care, plus tasty food is never far. On the 27th we flew to Berlin, and although Sarah was concerned about the regular plane noises, we landed safely :)