A highly rated aluminum decking brand is LockDry, according to ConsumerReports.org. Other brands include Versadeck and AridDeck.
LockDry uses a gap-less design that allows the deck to remain waterproof and practically maintenance-free. The decking itself is expensive, but requires less time to install as opposed to wooden decking.
LockDry features a standard, powder-coated design. However, it is available in several different colors, some of which are made to look like wood. The design of the deck also allows for space under it to be used, often as space for a carport or storage area. LockDry is available at approximately $7 per square foot.