We use a Directv satellite dish. We have Directv at home and added receivers for the RV along with a Slimline 3 dish on a tripod. When outside our home broadcast area, we use Distant Network Services to get NBC, CBS, ABC, Fox and CW broadcasts.
If we're located in a campground near over-the-air broadcast TV, and aren't there for long enough to bother setting up the dish, we'll watch TV from the trailer's rooftop antenna.
Every once in a while, if it's a 1 night stay, and we're not in range of over-the-air TV, we'll use campground cable TV.