I would go with the San Diego Zoo.
If you want to see sleeping animals and don't mind straining your eyes looking for them, then head over to the Wild Animal Park. Its definetly no African Safari.
Both places, most of the time the animals are just sleeping or scratching themselves. But at least at the zoo, you can leave and head over to Balbo Park and check out the musuems and the giant bontainica garden. Plenty of cute girls there also.