There are several fantastic resorts in St. Croix, but there are currently no St. Croix all inclusive resorts. The Divi Carina Bay resort in St. Croix has in the past offered all inclusive packages, but as of this writing, there are none offered. If you are going to stay in St. Croix and you want an all inclusive vacation, you should inquire with The Divi Carina resort as they may begin offering them or create one for you.
Go here for a comprehensive listing of hotels in St. Croix.
Here is a site with a listing of St. Croix hotel deals