You'll find quality shopping at air-conditioned plazas. Most of the Bruneians dollars probably went to the shiny YSHHB Complex. The complex offers a dazzling selection of goods from watches, sunglasses, Iranian chandeliers and other essentials. It stays open till late too.
Right across the bridge (through Kampung Ayer) is the huge Yaohan department store. It stocks a huge range of imported clothes, electrical goods and books whilst the supermarket in the basement carries a large amount of imported foodstuffs from all over the globe. Besides Yaohan, there are also a number of shopping plazas within close distance such as the When you're in Brunei don't miss out on some of their local drinks, which may not be original, but can be quite tasty. Coconut milk and fruit juices are local and often served fresh, neither of which is to be missed. Tea and coffee are also popular drinks in Brunei and can be easily found. Other drinks, such as milk and soft drinks are also available in the country.
As a primarily Muslim country, Brunei has no alcohol available and it is illegal to consume in the country.
The tap water is generally safe to drink in Brunei. If you do drink the water (or the ice or salads washed in the tap water), many people may have trouble adjusting to the local tap water as it will most certainly be different from what your system is used to if you are not from the region.