In short, visit longer and do more than I did. My post below will by no means give Belgium the credit it deserves. I only had 24 hours in the country and most of that involved taking public transport, buying food, and roaming the streets in order to find my hostel. Explore the different cities and throw yourself into the mix of French and Flemish cultural influences. Take the time to do as much as you can. That said, I hate to play up stereotypes, but definitely try the beer and chocolate. The rumors are true.

Overall Impressions

Brussels is fairly quiet in December.
The metro is slow and a bit dirty
Belgian beer rivals that of Germany as world's best
Almost everything is written in four languages: Flemmish, French, English, and German