Congrats Holly. It would help if we knew your budget in dollars, and where you're flying from.

UPDATE!

Budget isn't really an issue. Our parents have been kind enough to spare no expense and treat us very well! We are flying out of the United States also.

Which airport?? This can mean the difference between leaving in the morning and being on the beach shortly after lunch, or a long layover and a puddle-jumper connection, leaving your first day wasted by travel.

Well, we will be leaving from North Dakota so whatever the connecting flights would be. I'm not sure yet because I'm trying to narrow down where to go.

Out of the must haves on your list, Barbados pretty much covers everything. Though snorkelling there leaves a great deal to be desired, other islands have better snorkelling. However Barbados has the beaches, great restaurants, plenty of accommodation options that fit your criteria and is just a lovely island with great restaurants offering many types of cuisine. Catamarans offer sunset cruises as well as lunch cruises, the difference is some amazing sunsets can be enjoyed.

I'm unusure if Barbados has ziplining, it's a pretty flat island and there are no jungles/rainforests. It is not known for snorkelling although we were ok with what we saw underwater, its not as good as Aruba or St Lucia for snorkelling but Barbados covers most of the requirements on the list. Apparently there is snorkelling at Folkestone Marine Park, I have not been there so cannot comment. Have been on excursions to see turtles however, by Cobblers Cove.

From your list, none of the 3 are going to meet everything. Aruba has tons of great resturants and bars, but it's a flat arid landscape. No jungles, rain forests or zip lines. The snorkeling is pretty good, but not from the resort area. You will have to go to De Palm Island, Baby Beach, Arashi Beach, the Mangel Haltos or take a snorkle boat trip out to the wreck. Palm Beach is more crowed than Eagle Beach, but the Palm Beach area has tons of restaurants, bars, shopping and entertainment within walking distance. Aruba has a good public transporation system, so if you stay on Eagle Beach just take the bus down to Palm Beach for those things. Most people complain that Aruba is "too Americanized". We didn't see it like that.

St. Lucia has jungles, rain forests and zip lines, but we didn't think the food was all that great. Beaches are a darker sand and water a deep blue. Nightlife and snorkeling was meh. To us, it was more about sightseeing.

Haven't been to Barbdos yet, but from research, it probably ticks most of your boxes of the 3. However, make sure you check location as some areas have rough water and not really swimable. Your best bet for snorkeling is taking a snorkel boat tour. The highlighted excursion there is swimming with the turtles with additional snorkel stops.

South Barbados has rougher water, I wouldn't exactly say they are unswimmable, you can swim in them but the waves are big, which is fun for some of the water activities. The nightlife is concentrated around this area of St Lawrence/Gap. The calm Caribbean side is the west coast, where the better hotels and beaches are located. Barbados is a small island, getting around is not a problem. The east coast is the rough Atlantic side, not suitable at all for swimming, it's dangerous, but interesting to see this area.

Sugar Beach Hotel in St Lucia is situated near the Pitons, it has recently been renovated and has imported it's own white sand for the beach (this was done some years ago in fact). It was formerly called Jalousie, it looks really stunning. This area will have the rainforest but no nightlife except for whatever happens in the hotel. Best restaurants in St Lucia outside hotels are in the north, around Rodney Bay/Reduit Beach (which is a natural light sand beach with pale blue clear water), there is also alot of nightlife in this area, but you have to travel south to the rainforests. Marigot Bay also has some very good restaurants in a very romantic location. Northern St Lucia has lighter sand beaches, take a look at Windjammer Landings on TA for example.

Aruba is also a great fun island, doesn't fit the Caribbean image due to the landscape but the beaches are gorgeous. We're not American, but we also did not see Aruba as Americanised. It is developed and tourism is well and truly discovered in Aruba, just like Barbados.

"Budget isn't really an issue. Our parents have been kind enough to spare no expense"

If that's the case....I'd go with Musha Cay

Yeah, my pick would be Tahiti or Bora Bora.

After reading this and seeing that budget isnt too much of an issue, I would also choose Tahiti or Bora Bora. My husband and I were married last Oct and spent our honeymoon in Bora Bora and Moorea. 5 days on each island and it was perfect. From the water, the beaches, the food, the service, the spa, the adventure, snorkeling.....everything was amazing!!!!! We flew to LA from NYC area and then LA to Tahiti. Its a lot of traveling, but so worth the trip....especially for a honeymoon. We stayed in over the water bungalows which just added to the experience. We ate at our hotels and went out into town to some local restaurants. Best trip I have ever taken. There are so many resorts to look into there so I highly recommend doing that!