Tennis
Many of the hotels have a tennis court. You can use this by yourself or you can make a reservation with a tennisprofesional to just play a set or two or to give you a tennis lesson.
Horseback riding
There are several horse ranches on the island. You can explore Aruba on horseback in a totaly different way, see the sights you cannot get to by car and really enjoy nature.
Golf
Aruba has 3 golfcourses. The best known is Tierra del Sol, located near the California Lighthouse. This is a very luxurious 18 holes golfcourse with a great restaurant, bar and a nice shop. If you want to play golf less expensive you can go the the golfcourse
at San Nicolas. And recently there is a new 9 holes golfcourse called Divi Links. This golfcourse is located next to the camber of commerce at the low rise hotel strip.
If you have children you can go the Adventure golf and play a round of mini golf.
Bowling
Bowling is quite popular in Aruba with local teams competing abroad regularly. Shoes, accessories as well as snacks and drinks are available.