A Good Base for our Tuscany Stay

Without a car: Florence, in the city center. With a car: Any small town in Tuscany or even better, an agriturismo (farmhouse) in the countryside. Preferable areas (based on the towns you want to visit) are the areas between Florence and Siena, not too far from the main freeway which connects Florence to Siena. Wherever you are in the Province of Florence, south of Florence, or the Province of Siena, north of Siena, you will be no more than 2 hours from everything. For the Cinque Terre, you might need a little extra time, since it's a little removed from the core of Tuscany (actually the Cinque Terre are not in Tuscany, but rather in Liguria).

I may be in the minority here, but I like to stay inside the city of Florence for the following reasons: LOTS to do within Florence itself. Many museums, restaurants, the Glorious Piazzas!
Transportation Hub: saves the $$ on rental cars. You can get to Siena and many of the surrounding hill towns on a bus for a day trip from there. Apartments: many to choose from. Most in residential areas with local groceries, meat markets, pasterias, bakeries, etc. We always stay in Florence because in the long run it's less expensive to rent an apartment there and do day-trips. When we arrive after a day trip, it's easy to walk to a restaurant, or even just to cook in. Sometimes staying out in the hills just "sounds" so romantic, but when you have to drive everywhere, including restaurants, groceries, etc., and the hassle of having a car -- we just don't see it. I'm interested to see other peoples' opinions, however, and I will watch this thread.

We loved staying in the countryside between Certaldo and San Gimignano after a long weekend in Florence. It's just 20 miles or so south of Florence. Virtually every farm has rooms or apartments as secondary income. The area didn't have very many inexpensive restaurants, and we cooked most nightly meals. When doing day trips by rental car, we picnic'd or grabbed a piece of pizza in the hill towns for lunch. We especially loved Volterra. There is relatively little English spoken outside of the tourist centers, which doesn't bother us. We later drove down to Orvieto and spent the night in this fantastic hill town. It's a great place to turn in a Hertz rental car when getting on the 75 minute ride into Roma Termini.
Civita to the southwest of Orvieto is also an incredible site and well worth seeing.

We stayed in Montecatini Terme for 8 days when we went to Tuscany and it was very centrally located for day trips to everywhere. We had a car but the train goes there so you could get most everywhere from there by train. It's a short distance to Lucca, Pisa, Florence, Cortona, Siena, San Gimignano, Volterra, Arezzo - we did them all as day trips, sometimes two towns in one day. That was easy with a car but maybe not as easy by train. We enjoyed Montecatini Terme in the evenings, lots of restaurants and pretty quiet in the evening. It's a spa town and we did check out some of the spas but never actually had time to go to any of them.

I agree with Montecatini....loved it. Very nice town with lots of shops, restaurants, and easy to take the train to Florence and Lucca. You can take the tram up to the top and there are nice little restaurants up there, too. We stayed in a hotel right across the street from the park, where you can walk the trails. There is a beautiful carousel that is lit up at night in the town, and there is also the spa for treatments, if you wish. We loved it, and from there ventured to Sienna, San Gimignano, Venice, Lucca, Florence, Pisa. Enjoy !

I stayed in Arezzo September, 2012. I easily took the train to Cortona (1 hour), Florence (1 1/2 hrs) and Rome (2 1/2 hrs). Arezzo is filled with piazza's, restaurants, history, architecture and Churches. It has a lovely small town feel and the people were very friendly. It is very walkable city. I don't think you would need a car to stay there. Buses and trains will connect you to the cities you mentioned. Happy travels.

You can get around from place to place without a car, but exploring the Tuscan countryside and visiting any little village or taking any turn in the road on a whim means you need a car. I would definitely stay outside of the city... but I love the villages and vineyards of Tuscany and enjoy Florence for a day (then I have had enough). All depends on what you want to do... I have no problem entertaining myself and do not need tons of tourist attractions to make me happy.