I like rope the best.
Rafting has taught me the utility of cam straps. They will slip without a couple of half hitches. Eventually that deteriorate in UV light and can fail. It is best to double the straps for a long trip.
Ratchet straps are okay for large powerboats. They are responsible for deforming more canoes and kayaks than anything else. It is easy to oil can a boat and break its back. Never use them.