If you are contemplating going out to view the Atlas V launch of the Juno spacecraft today then by far the best place off Cape Canaveral AFS property is going to be Playalinda Beach. This will give you an unobstructed view of the launch pad from a distance of about 5 miles.
To get to the viewing point you will need to cross Max Brewer Bridge and go all the way down the road, past the KSC northern gate, to the beach. You will have to turn north for a way until you reach the first parking lot.
Park up and then cross the sand dunes to the beach. Head south on the beach for about 3/4 of a mile until you reach a fence. This is the NASA KSC boundary line and the closest you can get to the launch pad.
Looking south you will see LC-39B almost demolished, then LC-39A and the next pad round is LC-41 which is where the Atlas will launch from.
A detailed map of the beach can be found here. The parking lots are the white rectangles and the viewpoint for the Atlas V launch can just be made out by following SR-402 out to the ocean.