The best tile backer board will depend on your specific needs and the conditions of your installation area. HardieBacker with HydroDefense is a great choice for areas that are prone to moisture, while cement board is a popular option for its durability. Wedi board is completely waterproof and easy to install, but it can be more expensive. Durock board is highly durable and resistant to mold and mildew, but it requires an additional waterproofing layer. Ultimately, the best choice will depend on your budget, installation area, and personal preferences.