Activities on Aruba

Because we are planning a last minute trip, I try to collect some good information about the activities on the Island.
Are there some activities that are a must to see or to do? And is it wise to book some activities on forehand?

Tnx

In my own opinion, it is very helpful to book ahead for the activities you like to join with so that you'll be able to plan and maximize your time while you're on a vacation. Will you agree with me?

well there are so many activities you could join into once you arrive in the island. Would you prefer sightseeing, water or land activities? Yes, i would suggest that you book your trips before hand so that you will be assured that you will be able to take the activity since its already a high tourist season.