Jamaica: RIU Ocho Rios. Perfect beach and ocean, great food, not adults-only but not very many kids running around, perfect perfect place. Very romantic and wonderful. Lots of restaurants, there is a hot tub.
DR: Secrets Excellence Punta Cana. Adults only. Perfect, huge, romantic, no kids, tons of restaurants, no reservations required at any restaurants, perfect beach and ocean. You won't leave the resort, but won't need to. There is a hot tub and fitness center.
Barbados, Almond Casurina: pink sand, great food, safe and really cool island for exploring, some kids at resort but not too many, perfect perfect warm gentle waves in the turqoise water, very close to awesome town and great marketplace with fish fry; tons of activities. Small fitness center, no hot tub.
Also check out, based on what I have heard: RIU Aruba, Occidental Grand Aruba.
IMPORTANT: do your research on tripadvisor, and use your judgment to decide which reviews to trust and which ones are just unreasonable people complaining too much. You have to find answers to important factual questions like whether the beach is good for swimming. Don't assume that just because they build a resort on a particular spot, it must be a good beach. We went to Bluebay Esmeralda Riviera Maya in Yucatan, and the beach was horrible: rocky, slimy, unswimmable. Do your research before you book. If you go to any of the three I mention above, you will love it. It is very hard to find out whether resorts have gyms and hot tubs for some reason, and many in the carribean do not have hot tubs, they probably assume people don't want hot tubs in hot weather, but in my opinion this is a straw herring.