Hitch racks are ideal if you're looking to hold 3 or more bicycles. They are often also the simplest systems to use. Hitch racks are recommended for e-bikes.
Trunk racks are often the most budget friendly. They're a good option if you are not using the rack very often and are holding 3 bikes or less.
Roof racks and roof mounted systems provide the best versatility. Besides bikes, these systems can also allow you to mount kayaks, skis and similar sporting equipment.