I am not Islander but I would recommend visiting the USVI first and then visiting the other placesdown the road. It is a good starting point as you then eventualy get to compare the other places to St.John or St.Thomas. More so being that these are US territories.

Based on what I have read on other forums, people do just that and it seems that St.John is the favorite when it comes to describing paradise.

Kellye,
I think it depends on what you're looking for. If you want high rise American style hotels, lots of shopping, nightlife, gambling and things like the "Party Bus". Then Aruba will fill your bill. It's in the southern Caribbean where the weather is fairly consistent, hot and sunny. The island itself is dry and somewhat scrubby with nice beaches. Aruba does not have what one thinks of as a lot of Caribbean character.

The US and British Virgin islands have spectacular beaches, incredible snorkeling, shopping (mostly on St Thomas), in general, smaller lower rise hotels and many many private villas for rent. There are great restaurants and somewhat more subdued nightlife. (More subdued than Aruba that is)
The US and British Virgin Islands are close together and a connected by lots of ferries and puddle jumper airlines. It's easy to visit both the US and BVI on a vacation.
The USVI and BVI are more lush than Aruba, not as lush as someplace like St Lucia or Nevis. There is more rain than Aruba but normally showers are brief and the sun comes right back out.
Good luck figuring out what would be best for you. I'd suggest doing some Google searches, looking at lots of pictures, reading and searching message boards like this one. There's so much good info on the internet and so many people willing to help!
Happy traveling!
Janey

I would not recomend one of these three as OPPOSED to another. It really depends on what you personally are looking for. As I have no experience with travel to Aruba I can't not compare. In terms of the BVI and USVI, the USVI offers you a greater variety of activiites albeit in terms of water sports quite similar. St. Thomas offers you beaches, water sports, shopping, wonderful restaurants... St. John is very close and offers a much more laid back atmosphere. The two islands can be enjoyed in one vacation. Additionally St. Croix offers an atmosphere that is in between, it has shopping, beaches, a casino, restaurants and is fairly laid back. The BVI's are quieter in terms of activities but are beautiful and I would recommend visiting them. Perhaps while in the USVI you could take a day trip to the Baths in Virgin Gorda.

--Islander