Rennaissance suites has the grassed area along side the lagoon. Also, we have seen lots of receptions outside the casino in the grassed area. they set lovely tables, chairs etc and make it look really elegant. Its private both areas. I believe also that you can do it on the pool deck at the marina tower...outstanding view of downtown and the lighting up there is gorgeous. I would do it any of these 3 places...
Marriott has a new paved terrace as one option and another would be poolside. We just had our wedding there in October and we had the most amazing poolside reception! They also have their 'Atrium Terrace' outside the lounge bar but I'm not sure you'd want it for a reception. And ballrooms but I don't think anyone goes to Aruba to be indoors. =)
Here a pic from our first dance. The bar was to the right, DJ straight ahead (pool is behind the DJ) and a really cool lounge space to the left (lounge space was also on pool deck though it might look like sand in the pic). They had set up a dance floor. We chose to have dinner on the lawn with a canopy (that's where the person taking the photo was sitting), but there would have been plenty of room to also seat our group poolside. We had 43 guests. I have pics of both the poolside and the terrace during the day as well, but haven't gotten around to downloading them yet.
We're kind of hotel snobs and were first sold my Marriott's $50 million renovation but after that the people continued to exceed our expectations. They helped make our wedding the best weekend of my life to date! The Renaissance Ocean Suites pool is really nice and the Marina Pool Deck is an interesting idea though to us the hotel rooms felt dark and dated. But again who goes to Aruba to be indoors!?