Anguilla has some of the best, undisturbed beaches in the World with very little crowds. Not very populated if you vacation there, but it is awesome place to get away. Fly into Saint Martin the. Ferry over. Or, stay in Saint Martin for all the other things and take day trip(s) to Anguilla.
I bet we had a few miles of white sand beaches, beautiful waters and may 20 other people total for two days we were there. You just disconnect from the rest world.
We've been there twice. Stayed in a stunning villa in the Viceroy the first time, then at the same resort (now Four Seasons) the second time. It's my kids' favorite vacation spot on earth.