Wife and I stayed at Anse Chastanet in St. Lucia. It is beside, and lower down the hillside than Jade a Mountain that the other guy mentioned. Jade is about as plush as they come and considerable more than Anse. And that is saying a lot because Anse is awesome.

Any nice establishment on Seven Mile Beach in Grand Cayman. There is a Ritz there that is very nice but numerous others as well. We stayed at a B&B during our stay. The island itself has great beaches and water but not much scenery by way of hills for great vistas,etc.. Think the highest point is like 50 ft above sea level. What you lose in that regard though you more than make up for in feeling comfortable and safe. A lot of money (huge offshore banking center) on that island and you never really see the shanty towns you do on most other islands. Supermarkets are full service and like the finest we have in the states. Everyone speaks English with an accent between the European and American versions. Not nearly as British sounding but not quite American either. A good racial mix of about 60% Caucasian and the other 40% being mostly black. Got taken aback on our first day there when we were flipping through the radio channels in the car and heard the tail end of a Kenny Chesney song and the DJ started talking. Sounded like a southerner and was like "you're listening to Cayman's country music station." I looked at my wife and was like "where the hell are we?" Anyway, great place.

Barbados is nice but WAY to over populated. Friendly people abound and It's cool to drink some beer and watch a local Cricket match at night but just to many dang people crammed on that island.

St. Bart's was very nice and we booked a condo of VRBO there. Former French Colony so the locals tend to be a bit snooty . We felt a bit below our pay grade there but still had a nice time. And if terrifying white knuckle approaches in a prop plane plane would scare the crap out of you, take the ferry from St. Maarten. Several videos on YouTube of that nosedive feeling approach to watch.

Good luck. There are so many awesome islands to choose from. To me though. St. Lucia with the Pitons and hills is as beautiful and scenic as can be found.