I use to live in Port St John which is literally right across the River from Cape Canaveral. At the time, it was part of Cocoa, now it's its own town. We could walk out our door and see all the launches, even the "secret" ones that were never mentioned. Hard to hide the vibrations of a rocket flying into space.
The best thing that I have to say I ever saw was when they had the Discovery land at the Cape. It was the first time they did that and even though the show wasn't better than a launch, it was better by far just to see the brick glide through the air.
One year my grandparents visited us during one of the launches and we went to the campgrounds to watch it. Pretty much as close as you can get without being an employee or special invite. That was somewhere between 4 and 6 miles away from the launchpad.
The Challenger however went up and down while I was in Kentucky visiting family so I missed that one. Sort of happy and sad at the same time that I didn't see that one in person.