We have gone a dozen times and there is always something to do or new to see.
Make sure to stop by the Columbia restaurant for a 1905 salad and a half cuban, it wouldn't be a true trip to Ybor without it.
Take a stroll down Riverwalk, it runs from Armature works to Sparkman Wharf. You can take a river taxi to see the sights, visit one of the many museums along the water and of course find some awesome places to eat.
This beautiful garden was originally a sink hole that formed in the middle of St. Pete, but you wouldn't know it from the beautiful tropical plants and flowers growing there now.
Go early in the day so you can also visit Heritage village which connects to the gardens. It is outdoor museum that allows you walk through restored historic buildings from all over Florida