Favorite towns in Tuscany and/or Umbria

In Umbria: Assisi.

Second for Assisi!

Spello, Montefalco, and Bevagna, in neaby Umbria, can all be done in one day. Pitigliano sits on tufa cliffs and is very pretty. You could see tiny Saturnia at the same time. There are places nearby where hot springs bubble up, forming pools with stalagmites and travertines. Some are viewable from the road, or you can try to snag one of the limited parking places for the free bathing spot. Massa Marittima is another very pretty town, with a medieval (lower) section and a renaissance (upper) section.
In a very different vein, you might consider visiting one or the other of two outdoor sculpture gardens, Il Giardino dei Daniel Spoeri and Giardino dei Tarocchi. Very different from each other, and both very worth seeing.

If you have a car then Casteluccio.

Thanks for the suggestions...exactly what I was looking for! I notice that Perugia is on the way to Assisi (according to MapQuest, Assisi is only 20 or so minutes from Perugia); would it be possible to visit both towns in the same day or does each town deserve a full day?

On a separate note, I'm not receiving e-mail notifications when someone responds to my posting and it has been a while since I've asked a question...has the notification feature been disabled?

does each town deserve a full day?

OK, I'm biased, but Assisi deserves two or three days, or at least a day and a night. The magic is in the evening after the daytrippers leave, and in the early morning.

Question regarding Pitigliano...it looks wonderful but is it a "doable" day trip from Siena? After Tuscany, we will be turning in the rental car and finishing up our trip in Rome. I'm wondering if it would be better to visit Pitigliano en route to Rome and then drop off the car somewhere on the outskirts of Rome. Any input?

Montalcino and the Abbey Sant'Antimo

Spello and Spoleto in Umbria -- Spello very old, quaint and the aqueduct bridge in Spoleto is magnificent. Spello is close to Assisi and we enjoyed making it our base for the area.

Do the aqueduct walk from Spello to Collepino. I also agree with some of the other posters that Gubbio is worth a visit. Make sure you ride the funicular if you go there.

After looking at the pictures Jeff posted, I would say Assisi. I haven't been there yet, but now I want to!

Viamichelin shows the drive from Siena to Pitigliano as over 2 hours. For me, that would not be a daytrip. Visiting on your way to Rome seems like a better idea. We once made it our first destination after arriving at FCO. My recollection is that the drive was 2 - 3 hours. Though 1 night stops are not often recommended, it wouldn't be bad to drive down from Siena and stay over. Then, make your way to Rome the next day. The tufa cliffs and the hot spring limestone formations make the area very special.
Everyone is different, but I found that a day in Assisi was enough for me.

Since nobody suggested Cortona I will.
Anghiari is also at the top of my list.
Closer to Siena you might want to consider also the Val d'Orcia (Buonconvento, San Quirico) and the Alta Val d'Elsa (Monteriggioni, Colle Val d'Elsa, Certaldo).
I'll stop here to avoid day trip overload but I could easily come up with 50 to 100 locations in Tuscany and Umbria.

If you're remotely interested in St. Francis, his hometown of Assisi would fit the bill nicely. I spent two weeks there recently. Here are some highlight photos, if you care to take a look: Assisi Highlights April-May 2015

We thought Spoleto was wonderful. Toodled around the town, walked across the aquaduct bridge...very cool. There is a magnificent fresco cycle by Fra Filipino Lippi in the cathedral. We decided to have lunch, perused several restaurants clustered on a small square, and were headed to our choice when we saw the waiter from that restaurant walk next door to pick up his carry out lunch. Changed that plan quickly. We also visited medieval Gubbio, strolled the town and a large park for a day and Assisi. These were all daytrips from Perugia. The TI there was very helpful, recommended these towns and advised is as to whether train or bus was the best transportation option.

As has probably become clear, there's an overwhelming abundance of excellent choices. Don't spend tons of time trying to make sure you found the "best" one. Pick one that sounds good and go for it.

Michael you photos are fabulous. I spent 4 days in Assisi and your photos brought back many great memories.
I'm ready to go back ....

Todi isn't on the list yet? I just spent three nights in Trevi, loved it. Still a small town with local life (and tourists but not huge tour groups). Love Gubbio as well.

Assisi definitely needs a night or two to enjoy it without the day trippers, Spello is only a few kilometers away.

Since you've been to Tuscany, I would concentrate on Umbria this time.

The suggestions are all great...thanks for everyone's input. It will be tough to narrow it down as we only have 5 days in the Tuscany/Umbria area.