St. Kitts is very nice. Marriot is great - off season cheap rates.
St. Martin - Dutch and French side Maho Beach and Orient Beach (nude)
St. Barts - expensive - take a ferry from St. Martin Nice boutiques
St. Lucia - nice resorts - all inclusive resorts
Antigua - Jolly Beach resort - all inculsive
St. Thomas - close to being in US
Aruba Nice port
Puerto Rico - very nice, like being in states
Been to all of these including Nevis - nothing to do and expensive to stay.

When I was in Nevis, I flew to Puerto Rico over the break and took a 7 day cruise. Airfare was cheap and got to see a lot of islands down the chain.