I have recently been to several small hotels and B&Bs in Belgium that you should not miss:

The Patio Houses in Mechelen (lovely house with spa, friendly owners, great food): my review is posted here.

Verne Dreaming in Ghent: unexpected and over-the-top, it looks like a Shanghai bordello (review in Dutch).

Casa Bo in Falaen (Ardennes): a former girls’ school, it has been converted by a Belgian and American film maker couple into a peaceful getaway (review in Dutch).