Svalbard and Jan Mayen Islands
Svalbard has the aproximate size of Ireland, but almost no roads. There are only a few settlements, of which the main one is Longyearbyen. Even there, roads are almost just within the town. The exeption is the 6 kilometer road to the airoport, where also the campingsite is located (as a hitchhiker, you usually stay there). On this road, hitchhiking is super easy, almost each car gives you a lift. But there is another, quite extraordinary possibility to hitchhike: Go to the airport and ask the crews, wheather they can give you a lift. Not sure they will, but once it worked.