Stacia & I went to St. Martin twice this year, once in January, the other at the end of September. Both times we stayed at Grand Case Beach Club, in the village of Grand Case. Absolutely great place to stay, at night you can stay on the property (not all-inclusive) and eat at the Sunset Café (not to be confused with the Sunset Bar down by the airport where "Topless Women Drink Free.) We've also stayed at La Sammana, but that was ... Ouch! About ~$1,100 a night. Easier to get "in" at the ... it was called the Radisson Blue, or maybe it was a Sheraton. But, the availability is probably easier. Average rate ~$350/night. If you can get into GCBC, do that. Night life in Grand Case is a good time. Lots of little bars and places to just walk to and stumble back. Driving is ... challenging on SXM.
If you can, try to stay at the RIU. Great hotel and all inclusive. Also the Great Bay is pretty nice...great beach and close to downtown Phillipsburg. Orient Beach is nude and fun. Try St. Barth's or Anguilla for a day trip, great day trip and you can let everything out. Real sexy and gorgeous places.