With few exceptions the vast majority of hotels in Brasilia are located in one of the two hotel sectors: SHN (Setor Hoteleiro Norte, north hotel section) or the SHS (Setor Hoteleiro Sul, south hotel sector). The areas are within a 10-minute walk of each other, and of the city's two shopping sectors. The only variety is the level of luxury and size of the building.
The majority of hotel guests in Brasilia are politicians and businesspeople. As a result, demand for hotel rooms is huge on weekdays and almost nonexistent on weekends. It pays to schedule your visit to Brasilia on the weekend. (Most monuments are open Sat and Sun and closed Mon). Hotels often offer 2 nights for the price of 1, with dinner and drinks thrown in. For the same reason, low season in Brasilia is during statutory holidays, January and February, and Carnaval. If you must visit Brasilia midweek, book well ahead of time (at least a month).
Hotels are concentrated in their own area with few services around, so amenities tend to be plentiful; many hotels offer fine dining, shopping, salons, car rental, and business centers. Even when not staying at a top luxury hotel, you can utilize the facilities in adjacent hotels.
Lakeside -- The exception to the hotel sector rule are the hotels situated on the shores of the lovely man-made lake surrounding the city. Staying here means a minimum R$15 (US$7.50/£4) cab ride whenever you want to visit any sites or shopping or restaurants. But then staying at the regular hotel sectors will still involve a cab for restaurants and nightlife. And the lake is lovely. It's a trade-off.