I was so lucky to be able to go to Antiqua and Guam in the Navy. I personally loved "Half Moon Bay" in Antiqua and this beach offered body surfing and, going down a little ways from there, you could snorkel with actual live (not dead) coral! This was in 76'. The Navfac Guam beach was good and the enlisted beach hut area (I think) had the best section of beach.
Antiqua and Guam were pretty neat places, but I was extremely fortunate to have Pulled two tours in Bermuda and my last in Hawaii. For the best beaches, I would have to go with:
Bermuda: (1) Horseshoe Bay and (2) Jobson's Cover - both South Shore
Hawaii: (1) Bellows Beach (former AFB) and (2) Waikii
Nowhere, except Bermuda, can you experience the soft, powdery, pink sand of those beaches - "down de road, mon". ('66-'69 and '74-'77)
"Most unusual beach: Punaluu Black Sand Beach, Big Island of Hawaii ('78-'81)
I agree with Dee about Bermuda beaches, how ever "pawpaw beach" in Palmetto Point, Eleuthera was by far the most beautiful, uninhabited, beach I have ever enjoyed. I slept after many mid watches on that beach while the family swam and gathered shells. What a wonderful place.
Chuck