When you are in Brussels, depending on the art you like, the Fine Arts Museum also has a range of different expositions and musea covering the Flemish Old Masters (in particular Bruegel at the moment) but also romance (Wiertz) and fin-de-siècle artists. In Europe if you like more classic culture I can also recommend a visit to the opera or ballet, in Brussels that would be de Munt/La Monnaie.

For all European tourist destinations: avoid restaurants in city centers with shady men in front trying to get you in with special menu's. The food is rarely good and what you save on the food with an affordable menu you spend extra on overpriced drinks.