I'll be spending next weekend in SoBe..been there quite a few times. Places I've enjoyed over the years are Nemo's, China Grill, Pacific Time, Tantra, Astor Place, Delano Bar and Joes Stone Crab. Puerto Sagua, and Dave's Cafe for more "down scale."
Not all the most chowish..but fun. Boston's got some great restaurants but Miami has a vibe that stodgy New England just doesn't have. Any other places that people like now? dining..cocktails? I don't rent a car and generally stay in the fairly immediate area.