The 25-mile-long barrier island that starts with Clearwater Beach in the north and ends with Pass-A-Grille Beach in the south contains some of the most beautiful shoreline in all of Florida [1]. Most of the towns along Gulf Boulevard have public beach access, but some (Indian Rocks Beach, Treasure Island) are more generous than others (Belleair Beach).
True beach lovers will want to make the effort to get to the blissful environs of Caladesi Island, which is only accessible by boat.
Links:
[1] http://www.moon.com/destinations/florida
[2] http://www.moon.com/destinations/florida/tampa-bay-area/st-petersburg/beaches/honeymoon-island-state-park
[3] http://www.moon.com/destinations/florida/tampa-bay-area/st-petersburg/beaches/caladesi-island-state-park
[4] http://www.moon.com/destinations/florida/tampa-bay-area/st-petersburg/beaches/south-clearwater
[5] http://www.moon.com/destinations/florida/tampa-bay-area/st-petersburg/beaches/st-petersburg-area