tough question
My 1st trip to the "little latitudes", more than 30 years ago, was for 28 days on a Eastern Airlines special excurision ticket ($300, as many destinations as you wanted for 30 days). I picked up 1 of the soft cover caribbean guide books, Fodors or Frommers, and did the homework, had a great time. St Maarten, St Barts, Antigua, Fl Keys. Now with 3 passports full of stamps which is the best island? What was good when I was in my 20's might not be so good now, but I've never had a bad vacation. Rode out a minor hurricane on St Kitts and as a result, met a british couple who have become lifetime friends. Went to SXM when there was no traffic, stayed away for 20 years, now it's my favorite (I think)again, islands change but so do people. Went to Grenada after the "intervention" not knowing what to expect, had the best Italian food ever, go figure. Met a bartender on Carricou, named redhead, although he was completely bald. Gave him my Jimmy Buffett tapes and now have a free pass at his bar, went on a boat ride with "sir Cuthbert Snagg, knighted by Princess Margaret. But back to the question, what is the best island? for me it's the one on the board at the airport that matches the one on my ticket. Just do the homework and you will be on the "best" island every time.