If more is better, then Turks & Caicos is exceptional. Two separate island chains between the Bahamas and the big island of Hispaniola, Turks & Caicos is comprised of some 48 islands surrounded by more than 300 miles of shallow sand flats. Most of those flats are sheer walls that drop off into the Columbus Passage that plunges past 7,000 feet. Thus, wall diving is a mainstay of the diving.
Provodenciales - Provo for short - is the most developed of the Caicos chain. Large resorts, a golf course and casino keep visitors busy when they're not diving tall stands of pillar coral or walls at Northwest Point. Staying on Provo also gives access to diving at West Caicos and French Cay. There are all sort of resort options here and plenty of good beaches and activities.
Southeast some 20 miles is the lesser-developed Turks chain. Grand Turk has tremendous walls a short three-wood from the beach and the entire West Coast is a marine park. Coral archways and tunnels lead to dramatic drop-offs and visibility is consistently good. Laid-back Salt Cay seems to be frozen in time and is a great way to get away from civilization. The wall on its western shore starts in just 30 feet of water and the wreck of the HMS Endymion is always fun to dive.
American and Northwest fly into Provo. There is regional service to all of the other islands from there.
The U.S. dollar is the accepted currency and English the official language.
There is a $15 departure tax.