Our family of four stayed at the Hotel San Pio last August. We were looking for a quiet, charming hotel away from the hustle and bustle of Rome, yet accessible to everything. And that is just what we found!
The room was large enough for our two teenage girls to have their own sleeping (and television) area, while we had ours. The gardens are lovely, and provide a much-needed oasis upon return from a day at the Vatican, etc. The extensive breakfast was accompanied by classical music wafting through the gardens, as we ate our meal sitting at a table amidst the trees. Everything about the hotel was just lovely, and an absolute steal at the 150-euro price we paid. This was by far the nicest hotel we stayed at in all of Italy, and the best value for the money.
Also, there are great local restaurants nearby.
As others have noted, Il Bucatino was terrific - particularly memorable was the extensive antipasto buffet, complete with dozens of platters of fish, meats, local vegetables, tomatoes, etc.
Those who want to be in the midst of the Rome tourist scene can stay near the Spanish Steps. For the rest of us, there are special retreats such as the Villa San Pio.

The San Pio is in a quite locatation about a 15 minute
walk from the Coloseum and central Rome.
The property is well cared for and the public rooms and dining area are first rate.
Breakfasts where good plenty of fresh fruit, bread,and cereals. We had a very good evening meal in the restaurant after a heavy days walking and can reccomend.
Rooms and bathrooms are spotless and for the rate we paid 90 euros through venere represents great value.
The reception staff could be a bit more warm, but the overall view is of a well run quality hotel.

We booked this hotel at very short notice and got a great deal for a one-night stay. Despite a few hitches in finding the hotel (which did, however give us an entertaining and informative tour of the ring road and suburbs) we arrived to a friendly welcome and joy of joys – free secure parking. This is on a first come, first served basis, but street parking is also plentiful.
While the hotel is not in the center of town, Rome is fairly manageable on foot and the twenty-minute walk to the center of the city is a pleasant one taking in the Circus Maximus, Colosseum and Victor Emmanuel monument. Alternatively the Circo Massimo metro station (or Piramide) is only a five or six minutes stroll away.
The Aventine hill on which the hotel is situated is a quiet and leafy residential area and after the frenetic center it is wonderful to get a good night’s sleep and wake up to birdsong rather than deliveries and what sounds like somebody repeatedly dropping a steel drum on the pavement just for fun. The restaurants of Trastevere are a ten-minute walk away and taxis are plentiful for the journey home when one is feeling well fed and a little less agile.
The hotel itself is rather grand for a three star establishment and the rooms have large comfortable beds, mini bars and clean, well-equipped bathrooms. Some have balconies and although ours didn’t it was still light and airy. A final remark is that the breakfast is varied and plentiful which is most unusual for this part of the world. Despite being very fussy generally, I can’t fault the place – highly recommended.

Decided very late on to take the family to Rome. I done a little homework and ended up being housed at the magnificent Hotel San Pio. At first we were given a room with a balcony that was on the smallside, but views of the small courtyard made it work. The staff were all very pleasant, and spoke English very well. They could not do enough for us. I am fortunate that I get to travel to Europe on a regular basis. Should you be visiting Rome, I would strongly recommend the Hotel San Pio.
My one down comment about the San Pio is that they have a sister hotel (Anselmo?) about 100 yards away which has just opened after refurbishment. The hotel staff gave me a guided tour and although it may be a little more expensive than the San Pio, I would try to stay there to enjoy the luxuries that it has. It is classy. Regardless, they are both magnificent quaint hotels that I would not hesitate to use in the future. You cannot go wrong by booking either of these hotels.