The video from the last test of Trident D5, launched from offshore, was unreal.
Someone happened to catch it with a good lens from a fairly dark hilltop, and then spacecraft experts annotated the video to point out what was going on.
You could see the bus rotating and ejecting warheads (or decoys) all the way through its inventory. Amazing.
I'm told by family that it's even more amazing to see the RVs re-entering overhead if you are lucky enough to be downrange during a test.
My favorite launch memory was of a Delta II night launch at SLC-2, from an elevated position on north base. The flame seemed to light up the horizon, and when the sound hit there was a power to that thunder that really must be witnessed firsthand to fully appreciate.
Conveys your sentiment regarding how it really sounds to be there. It unfortunately cannot convey the actual feeling of being there, and the impact of the launch on the body.
Edit: Here's an article that seems to have the video embedded, with a link to the annotation.
Around 5:00 minutes, the vehicle seems to shed smaller objects.