Just came back from a week in Aruba and had some great dining experiences with my wife. If you are in to fine dining check out the following. You won't be disappointed.
Barefoot - More on the casual side but great food. How bad can it get eating fresh fish with a bottle of wine while sitting at a candle lit table staring at the ocean in shorts and flip flops
Aqual Grill - A little less casual but still a comfortable setting. Try the blackened grouper. Fish was very fresh and just an all around pleasant atmosphere.
Ruth's Chris Steakhouse - Very elegant and a bit on the costly side but service and steaks were excellent. We went there for our anniversary and were not disappointed. We went back twice.
Ruinas Del Mar at the Hyatt - Whatever you do get a table on the "patio". It overlooks a koi pond and very romantic. Foods was great and our waiter was very pleasant.
Madam Jeannetts- Everybody's favorite. Outside dining in a great atmosphere. A bit noisy as the restaurant has about 50 tables. Good live music and a very friendly wait staff. I had the rack of lamb that was exceptionally tender and very tasty. My wife had the almond crusted grouper that was also exceptional and the portion was enough for two people. If you've ever been to Cabo, this restaurant's atmosphere resembles Edith's