Puerto Rico vs. US Virgin Islands
 

My boyfriend and I who are 20 are looking for a place in the caribbean where a passport isn't necessary. Neither of us have ever traveled in these areas and don't know which would be the better choice. We're looking to spend 2000$ each for 7 days and do the most. We want a nice place to sleep, but We also want sight seeing and activities to keep us out of the hotel, as well as great beaches to swim in and snorkeling. A great night life and great food is also important to us. A place that's easy to get around by foot and allow us to see the most. We want a trip we'll never forget

$300 gift to USVI tourists:
http://www.visitusvi.com/package_and_promotions

We loved the Buccaneer on St Croix. Click on my name to find threads about our stay there.

I would definitely look at the Virgin Islands over Puerto Rico. St Thomas has plenty to do, and the water is amazing. I also loved St Lucia, such a beautiful island. Not sure if you know Spanish, but we found the communication gap in Puerto Rico to be pretty extreme once we left the main tourist area (we know very little Spanish currently).

<<I would definitely look at the Virgin Islands over Puerto Rico.>>

I don't know why you would say that. Both places have a lot of what the OP is looking for. And neither has everything they are looking for (their wish list is for a place that doesn't exist). I've been to Puerto Rico scores of times over the years. There is a lot to do on that island if you are so inclined. Old San Juan will have the food. culture and nightlife they OP wants and easily navigated by foot. Great beaches and snorkeling are also available, although outside the San Juan metro area. I've also been to St. Thomas, although only once - last summer. I loved it there also but Charlotte-Amalie is no Old San Juan. The beach was beautiful in St. Thomas and the ease of getting to St. John is also great. We stayed at the Ritz Carlton, which was fantastic. It could be within the OP's budget, depending on time of year.

What I am saying is that both islands could provide for a great vacation. If I was the OP and was considering both islands, I would do some more research and work up competing itineraries for each island and come back with more specific questions.