There are many different types of HVAC systems available, each with their own advantages and disadvantages. Some of the most common and best HVAC systems include split systems, packaged systems, variable refrigerant flow systems, geothermal systems, ductless mini-split systems, boiler systems, radiant heating systems, heat recovery ventilation systems, chilled beam systems, and evaporative cooling systems. The choice of the best system will depend on the specific needs of the building and its occupants, as well as the climate and local building codes.