Cellular 4G internet, and Satellite TV would probably be the most common, though some campgrounds offer wifi and cable TV hookups.
EDIT: If you have Dish or DirecTV at home already, you can just buy a 2nd dish with a tripod mount OR one of the dome type auto/semi-auto satellite antennas and then just bring one of your set top boxes from home, no extra monthly fees.
If you have cable TV now and don't want to switch (or be locked into contract), Dish Network offers prepaid monthly service, though like most prepaid services you have to buy the set top box at full price first.