We love Aruba. We've been there once on a cruise and are going back next year.
We got off the cruise ship and basically walked down the line of waiting cabs/cars for hire, chatting with the drivers.
We found a driver we liked and for $50 each for the 2 of us he took us everywhere.
He was very knowledgeable of the island and took us to the usual tourist spots and to a LOT of other places the tourists aren't going.