If you are planning to watch the Delta IV WGS-4 launch on Thursday evening then you will probably find that there will not be too many people joining you and you will be able to get your pick of viewpoints.
There are 2 great locations, SR-401 by the Cape Canaveral Air Force Station gates and Jetty Park. Moving further afield just about anywhere on Cocoa Beach will get a good view, but not until the rocket has left the pad.
As the launch is in the evening after dusk then Jetty Park is likely to be shut so that really only leaves the option of the SR-401. This is about 8 miles from Launch Pad 37B and has a full unobstructed view of the rocket over the waters of the Banana River.
Click here for a detailed Google map.
Below is a video of a Delta IV heavy launch shot from form the SR401 viewpoint: