Depending on how you want to enable them, for a 3-way Fridge running on 12V, a basic 30/40A 5-pin relay for a couple of quid is a good way to go if using a D+ signal to control - reasonably reliable and available from loads of places on-line as well as places like Halfords and other Motor Factors so dead easy to replace if need be.
Another popular way is using the TEC3M Relay that uses Voltage Sensing to switch on. Common for towing electrics and the switched 12V is the typical "Fridge" circuit in caravans and also used in Campers. Again very easy to find if replacement is needed.