If you've been on the Carnival Splendor for the 7 day Mexican Riviera Cruise. Excursion suggestions?

Going on the Carnival Splendor 7 day Mexican Riviera Cruise in September with my husband and our 16 month old daughter. If you have been on this cruise or to these ports I am looking for suggestions on excursions that were awsome! Or suggestions on which ports we should plan an excursion and which ports we should just check out on our own. I am definately into walking the streets and shopping for some good deals!! Jewelry, purses, anything! :)