I spent three weeks in Tuscany over Christmas (with a side trip to Venice) and was generally underimpressed by the food. (The ingredients were another story -- I got a jar of whole black truffles fo $6!) However, there were a couple of memorable meals that need to be shared.
The first was in Siena, at the Osteria Da Fiore. I usually try to avoid the most guidebook-lauded restaurants, on the theory that they will be overcrowded and not very good. This was an exception (though the only other people in the restaurant were Americans) Absolutely if you go there, you must try their starter of a pecorino dumpling with rosemary honey and arugula. It's a small phyllo package of pecorino served with honey and balsamic vinegar, and is absolutely TO DIE FOR. I also had an absolutely delicious lamb dish -- the kind of fatty European lamb that they cook with garlic until it falls off the bone -- lamb shanks I think. Not what we get in the US but really tasty.
The other memorable meal we had was in Pisa. It was at a restaurant called Cagliostro (I'm not sure of the address, but it's on a side street that runs between the main street with all the shops that isn't close to the tower and the beautifully decorated building, north of the river. Pisa is small. Our hotel recommended it) This was inventive, exciting and very well executed cuisine. The cheese souffle appetizer, Bisteca, and excellent wine list stand out in my memory. We had a three course dinner for three people, with premium liquors to begin and a very good bottle of wine for under $100. Good value, great meal.