My wife and I have been going to Europe annually for about 35 years. The first airline to fly non-stop from Atlanta to Europe was Sabena, the Belgian airline. Even when it got competition, Sabena was much cheaper, so my wife and I flew it about 17 times, before it went bankrupt. We always stayed in Brussels for a couple of nights, so we became VERY familiar with the lobsters, frites, chocolates, waffles, beer and mussels there.
Leonidas was the VERY inexpensive locals' chocolate, sold out of shop windows all over town, to people in line on the sidewalk. Even with the depressed dollar it only goes for $6-7/pound today, about 1/5 of what it sells for in NY or on the website. Although it had no prestige there, we always thought it to be excellent, for 1/2 - 1/3 of the "better" chocolates sold there.
The very "best" in Brussels were either Wittamer or Mary, but they were fairly expensive. The Wittamer shop, near the Place Gran Sablon, is absolutely breathtaking. Others, such as Corne' Toison d'Or, Neuhaus, and Godiva (much better than the USA made version) are excellent. Corne', Neuhaus, and Godiva go for about 1/2 of the USA price, or about $20-22/pound.