best thing i found to do in san juan was to pray that my taxi wouldnt fall apart and that our driver wouldn't kill us.
If you like historic architecture and churches go to old town... if after the taxi ride you need a drink, go to the bacardi tour.
We stayed at the caribe hilton before a cruise. The wyndam across the way, with the casino, after the cruise. Didn't want to go anywhere but to the ship or to the airport.
Personally i found the people rude and snobbish, getting service even at the airport was impossible. I couldnt wait to get to miami...expensive, rude (except at the resort where they are paid well to be nice), and the city area showed a dirty, poor place, falling apart and building at the same time. beggars selling water at traffic lights...not the place i want to tour.
We go on our next cruise in Dec from san juan i will do the above mentioned praying till i get to the ship and save my time and money for better islands.
We got stuck on the RCCL adventure in san juan because of a dockworker strike it was strange, the govenor was negoiating but no cabs or trucks were allowed in the port. Princess was behind us and must have used thier crew and paid some scabs because they unloaded while we sat...we didnt care because we got an extra 6 hours, with lunch, and didnt have a flight to catch. I hope they don't do that often because we didn't book a room this time.