St. Thomas and St. John, and while you're there, take a ferry to the British Virgin Islands for more diving. I've only snorkeled in the BVI (and sailed) but would love to go back to dive. Lots of islands close to each other, lots of dive sites, lots of great restaurants and excellent lobster, plenty of everything. St. Thomas is quite touristy but still a fun place (try the Rum runner drinks at Fat Tuesdays). The 99 stairs are fun to experience as well. We missed a flight coming back from Tortola one time (our ferry back to St. Thomas was late due to poor planning on our part) so we had to spend the night on St. Thomas. It was great!! Are you using Marriott points? I've looked into that myself. St. John looks beautiful and romantic with lots of beaches and few people. 2/3's of the island is national forest (or park). Tortola and Virgin Gorda have great dive sites and top side entertainment as well (in the BVI). All these islands are close to each other which makes it easy to see and do lots (or little). My husband spent one vacation on St. Kitts and was unimpressed (said it was boring). Enjoy!