Go to St. John!! Heard a few cruisers mention that Meagan's Bay (the popular beach on St. Thomas) is VERY crowded.
--Get to the Baths in Virgin Gorda but if possible, book privately before you cruise and DO NOT use Carnival's shore excursion as your means to get there!!! You've been warned! The ferry brings hundreds to Virgin Gorda where many passages through the incredible rock formations allow one person to pass through at a time (while crouching, climbing, ducking, etc.). Going through them with such a large group takes away from the experience. Allow time for the beach AFTER you go through the Baths, as it is bigger and nicer than the beach on the entrance-side. To avoid the crowds from the ship-sponsored excursions, maybe getting there later or earlier in the day would help. I tried to book through Patouche Charters or White Squall but they were booked over a month in advance so I'd recommend booking as early as possible to avoid being stuck with the Carnival tour (which will book by the second day of the cruise as this is an incredibly popular excursion). With the large numbers they took, it was inevitable that a few cruisers apparently didn't pay attention to time and kept our ferry in Virgin Gorda an extra forty minutes and got us back almost an hour later than scheduled. Two Carnival employees for these hundred or more cruisers seemed unable to keep track of everyone and thus, we all suffered for the irresponsibility of either them or the two or three cruisers themselves. Either way, this would seemingly have been avoided with a smaller excursion. --a group raved about a locally-found, generic-sounding "island tour" for $20 offered by locals at the end of the dock.