I think Aruba is a great choice! We have gone with our kids 5 times. A couple of big factors we considered was safety, things to do, and drinking water! We have been burned by bad water on other islands, so the fact that Aruba has a massive desalinization plant meant we could go to any restaurant and not worry. We usually rent a car, as it is easy to drive around the island. That said, there is plenty to do if you don't want to drive. We have stayed at all of the Aruba Marriott properties, and each one has good and bad aspects.
If you have young kids I would stick to the on of the Vacation Resort properties (Surf Club and Ocean Club) or the Marriott Resort in Palm Beach. While the Renaissance is right in the middle of the downtown, and the island is a neat place to visit, it just doesn't feel like a resort. With your college aged kids, I probably would still suggest Palm Beach in general over downtown and constant boats back and forth from the Island. If I have to pick a place, it would be the Marriott Resort and Casino. Even though it's the oldest property, it had the best amenities for what we wanted. I felt like it had the best pool and beach to rooms ratio. I have a ton of suggestions on things to do there, but I don't want to blather on. Suffice it to say, you will be happy with the Marriott Resort, the Surf Club, or the Ocean Club.
Our family of five went to Curacao through Marriott Vacations and it was the best. The island has a lot to see, the people were friendly and we felt safe throughout the trip. The hotel has its own beach and a private snorkel area, which was very nice. The sunsets from the beach are fantastic. The pools and hot tubs are very good as well. There are a couple of dining areas in the facility and a small casino. The room are kind of bland, but in Curacao the rooms aren't that important. The hotel was very close to Wilemstad which is a delight. You can book day trips in the lobby and even rent a car. I would recommend renting the car at the hotel rather than at the airport and we found the airport rental desks sketchy at best. It was closed when we tried to return the car. Over all Curacao is our favorite island in the Caribbean with Aruba second.
P.S. At time of travel our kids were: 15, 21 and 25.
Have a great trip; we have been going to Aruba for the past 6 yrs (own a TS at the SC); our son was 23 when we started; he loves it; the Surf Club has a great gym, swim up bar, adult only pool, of course palapas on the beach and a small restaurant; it is walking distance to the main strip in Palm Beach; next door is the Ocean Club Time Share caters more to adults; Stellaris Hotel and Casino is next in line on the beach with all amenities and last is the Ritz Carlton the most unscaled property
I think the property you choose will depend upon what you are willing to spend