If you just plan on staying in a resort (the resort section of the island) and hanging out at the beach/resort pools and shopping...Turks and Caicos is hard to top.
But if you want to get out of the resort area and do some hiking and outdoor stuff...then I would probably recommend St Lucia.
If you want to go to an overall more modernized island...then my recommend Bermuda (pink beaches and rock structures are cool there). But the Brits can act real shitty to the locals there...watching the way they treated the locals was enough to piss me off. For whatever reason, they look at Bermuda as their place to escape and treat the island and the people like they own it.
Although there are some ok places on these islands, I am not a big fan of St Croix, St Thomas, The Bahamas (too crowded)....
Just my 2 cents worth.
ETA...I have been to a lot of the islands and honestly...I have never been to one that was BAD. Some had bad sections, or bad features, or bad entertainment options....but if you are flexible and open minded...EVERY SINGLE ISLAND I have ever visited is awesome!
This post was edited on 4/22 at 9:32 am