Hi Mike. I would personally list what factors are the most important to you as the Caribbean can offer different appeal Obviously one of the main draws is the beaches but do you want the steel drum influence the meringue or raggae influence etc.
The reason I say this is because they can vary quite largely, eg IMO Antigua is a largely flat and uninteresting island and unless you spend big bucks the quality of the rooms decor etc can be quite basic but the beaches are true picture postcard and you get what I call "the steel drum feeling" and it largely doesn't feel overcrowded, on the other hand Jamaica is a fascinating/diverse island and although certain beaches are beautiful and largely calm ie Negril the vibe is more in your face and not as relaxing imo.
Would you consider the Caribbean Mexico?, as we have stayed there a few times and the value for money you can find there I feel can be very good.