The best pasta I've ever eaten... La Giostra is a neighborhood restaurant within walking distance of the Duomo. We had dinner there one night during my stay in Florence, and I absolutely loved my meal — spaghetti with seafood in a slightly spicy white wine sauce. The pasta was obviously freshly made and just perfectly prepared. Although I usually eat only a portion of each course when I'm on a Fam trip, I ate every bite of this dish. It was worth every calorie!
La Giostra is a scene — every table full, not the fastest service in the world, but crowded, noisy, and popular for a reason: great food! It's open for lunch (on weekdays) and dinner every night from 7 p.m. and has great wines (and waiters who know them). La Giostra in Florence is located on Borgo Pinti, the concierge at your hotel can take care of reservations.
La Giostra Florence (search here on Google)