I think by the time I found this hotel I might have accepted a pigsty, but it is far from that and I struck lucky.
The rooms are large and en suite with telephone and multi channel TV. It cost me €60 for the night, including a very reasonable breakfast.
The location near Place Louise makes it convenient for the metro and there are innumerable places to eat on the way. On the other hand, it took me less than 20 minutes to walk to the Grande Place.
An unusual feature was that they let me keep my luggage in my room until 2pm. (I was less delighted when I found myself waiting while the lift was undergoing routine maintenance -- my room was on the 6th floor!) Never have I spent so little time at an airport as after this!