Curacao -- we did a 3hr bus tour with Irie Tours. Saw a lot of the island and had a 45 minute visit at Aquarium/Mambo Beach. Free water, soda and Budweiser while on the bus. The guide/driver was good and a tremendous value at $20. Recommended. Also loved downtown Willemsted, just across the Queen Emma Bridge. Very walkable safe port.
Aruba -- we rented 3 wheeled motorcycle liked vehicles from Trikes-Aruba and did a 3 hour tour of the island. It was AWESOME! My husband loved driving and I loved riding and sight seeing. What a way to experience Aruba's coast, historic sights and towns! There are only 3 trikes for rent and the tour leader drives a jeep. Best tour we have ever done in the Caribbean. Strongly recommended-reserve early.