My husband and I went to St. Martin on our honeymoon 11 years ago and we loved it! We stayed in a small villa complex near Oyster Pond - just over the border into the French side. We preferred the French side, is was quieter and less touristy. The restaurants were amazing. I highly recommend
Le Santal restaurant. It was the best meal we have ever had, and the most romantic. Be prepared to spend a lot though. It was also the most expensive meal we've ever eaten at $340 including a $60 bottle of wine (the cheapest they had) but we figured it was our honeymoon! Then again, there are people out there who would spend that much on the wine alone! I can only assume, it would cost even more today. There are many other excellent restaurants though, that are less expensive. Make sure you drive in a circle around the island, visiting all the different beaches, and take a drive upto Peak Paradis!