Wood requires maintenance to stay looking nice. Pressure Treated wood will turn gray,shrink, crack and warp very fast if not treated at least every other year. More expensive woods like mahogany and cedar need yearly treating to keep there new color. Composite requires little maintenance. It will fade from the sun and if you keep your grill on it grease stains are impossible to get out. Also composite can look wavy if the joist supporting it have large crowns in them. So there really is not a best it’s a preference. If never staining your deck sound great than composite is for you. If you like the look of wood and can maintain it than wood. There is a maintenance free wood called IPE or "ironwood". It's a very durable form of mahogany. Pressure Treated is the least expensive while mahogany, cedar and composite are about the same.