I lived in Saint Petersburg for almost 9 years, the pinellas county typically has better restaurants than a more commercial tampa side. Each city on the coastline is ethnically oriented: Tarpon Springs (mostly Greek) with incredible greek restaurants on Dodecanese near the spongue docks; Dunedin is largely Scottish (Celtic); Clearwater (Beware of scientologists). Best beaches are Madeira beach and the board walk, Treasure Island (Caddy's), st. Pete beach as well.
Tampa try the Columbia, there are some nice places at the International Mall, South Howard Ave has a lot of park and walk bars, and one thing i loved about the area there are no shortage of dive bars.
Top of Hyatt Regency on Courtney campbell causeway, Armani's restaurant with incredible view of the bay area. Bern's Steakhouse has been #1 in the country for some time; Oyster Catchers great seafood, Samarai Sushi in Ybor,
World of Beer is pretty awesome too.