Hi!
Congratulations!

Well I will tell you what not to do and that is go the commercial route of Couples, Grand Lido or Sandals resorts. There is just something about being one wedding out of 7 that day that I feel takes away from the romance.
So something different is a very good question. First of all, any suggestions has to be based on how many days you plan on going away for so you meet the destination's legal marriage requirements. And secondly the amount of nights also translates into where you can go to. Plus your departure city. If can only take off 4 nights then you should not go over 5 hours in total flight time each way. You don't want to be spending the majority of the time getting there only to enjoy just two days because of travel time. Lastly you should gear it to what the two of you like to do. Do you have a hobby or an activity that you like doing? A few years ago one of our consultant's had some scuba divers have a wedding underwater. Those are some choices you can look at.
As for different places out of normal, I would see if you can get to St Lucia. There are some very beautiful waterfalls or cliff areas that are very beautiful for just a couple to enjoy. Actually you could have a waterfall wedding in Jamaica too or maybe at Rose Hall a old historic plantation. So many destination wedding couples look to the beach that they forget there are so many other places to have a wedding. That is where you will find something different. Maybe a historic plantation in Grand Cayman or Jamaica, a fort in St Kitt, a tropical garden in Puerto Rico or a waterfall in St Lucia. There are so many places to explore that are different because it is not the beach.
Hopefully those tips will give you some more ideas to find a spot that fits the two of you! Best wishes on your special day
Take care,
Lindsay