If you are looking for a hotel near Brussels Airport, a good choice is Hotel Golden Tulip Rainbow. The rooms are generally quite expensive, but they offer several discounts on weekends, and if you are staying the night before you fly out of the airport.
The room was very comfortable and clean. The bathroom seemed to be newly remodeled. Tea and coffee were available in the room free of charge, and a fully-stocked minibar was also available.
The staff was very helpful. We required a taxi to the airport in the morning for an early flight, and they arranged that for us. A free shuttle usually runs from the hotel starting at 7:00, and can also be taken from the airport to the hotel. Otherwise, a taxi costs about 18 euros.
Breakfast is included in the price of the room.