I can't recommend Villa Pandolfi Elmi strongly enough. We travel to Europe at least yearly and always stay in small B&Bs - this is without a doubt the best we've stayed at. The villa is an old manor house just outside of Spello (about a 5 minute walk) and is just gorgeous. The house was built in the late 1700s and is filled with antiques (our bedroom was an old library and had beautiful frescoes in it). On the grounds is an old chapel that is absolutely beautiful inside along with a garden you can relax in. Access is easy from highway and parking is just inside the courtyard (a major plus for a hilltown). Fabrizio, the owner, is an amazing, outgoing man that speaks perfect English and will happily share his love and knowledge of the house, town and region that he grew up in. He is a great host and he and his girlfriend treat you like you are a member of their extended families. They truly made our time in Spello!
As a sidenote, Spello is a fantastic base for exploring Umbria. Not only is it a very scenic town in its own right, but its a great central location for day trips in Umbria are a hour or less away, eg Perugia, Spoleto, Gubbio, Assisi, Montefalco, Todi. I looked at a lot of different places to base ourselves and Spello just made sense: central, tourist sights but not touristy, hill town, Roman ruins, great restaurants, easy to get to, lots of reasonably priced accomodations, etc. Because its so close to Assisi we were able to easily stay late in Assisi and get a feel of it in its untouristed form without dealing with the overpriced accommodations and mediocre restaurants.