We stayed at Ocean Gallery just south of St. Augustine a few times and it was very nice. The historic town is very interesting but it can be crowded. The beach at Anastasia State Park is great because they do not allow dogs or cars and it is easy to get away from people. On that beach, the sun sets behind you, so it is good in the evening.
To get away from the crowds, you can drive south to Fort Matanzas where there is a beautiful beach and also go to Washington Oaks state park. Just south of the state park is a very good BBQ place.
Here is a music video filmed in St. Augustine.
Thompson Square - Are You Gonna Kiss Me Or Not (Official Video) - YouTube