Day Trips from Assisi

How about going to Orvieto?

We love Orvieto too. It's right on the north-south toll motorway, and taking a train into Rome takes just over an hour.

Last time we stayed on an agriturismo, we were close to San Gimignano. It seemed to be more hilltowns and travel sites in the heart of Tuscany--vs. staying as far south in Assisi.

Have a Armed Forces Vacation Club deal for a place in Assisi for $300/7 nights hence the home basing there. Didn't book it yet though as wanted to do my due diligence with vacation planning to see what our itinerary would be for the week. Been to Italy a few times, seen Tuscany towns by car but was backpacking so only stayed a night here or there and kept moving. Never been to Umbria though. I read on here that many people feel Umbria hilltowns are as nice as Tuscany. What towns are worth visiting for a day trip from Assisi? Seen a few convos on here about Spello, Spoleto, Trevi and Montefalco..never been any of them. Also thought Montepulciano, Siena and Cortona were good options and not a horrible day trip.

There are lots of great places nearby without having to drive far. The list below lists great places under 1hr drive from Assisi. Plot them on a map and build a sensible itinerary. You can hit more than one in each day trip since they are small.
Perugia
Spello
Bevagna
Gubbio
Foligno
Spoleto
Passignano
Castiglion Del Lago
Todi
Cortona
Anghiari
The last two are in Tuscany, the rest in Umbria.
All other places you mentioned, and also Orvieto, are at least 1.5 hours away.

Thanks Roberto! We would be flying into Rome so thinking we could stop at Orvieto on the way to Assisi

Spello and - undeservedly overlooked - Foligno are around the corner. Spoleto is an absolute beauty. (Don't forget the Basilica San Pietro, just outside the city proper.)
Perugia has it attractions (but possibly a nightmare to drive). Further on Cortona is another beauty of a hilltown.
Urbino is another interesting destination, but possibly a little bit more than you'd like to drive.