Just stayed there a month ago. There are several restaurants if you walk down the hill toward the Metro on Via Veneto past the U.S. Embassy. Short walk, 3-5 minutes. There is one right before the Metro entrance on the right hand side if your walking down the hill. Can't remember the name but the food was great and the price was very good also. About $10.00 to $12.00 a person. Not including wine but I don't drink. You really can't go wrong but we ate dinner there several nights and never disappointed.
If you have a chance, go to Trastevere, which is filled with great small restaurants with authentic Italian food and incredible ambience. I've found most of the restaurants around the Grand Flora to be very expensive. Harry's Bar is definitely not worth the kind of food they serve; Ristorante Veneto is very good but very expensive, as is a restaurant that I think has Paris in the name. At the curve down toward Barberini station there are several restaurants that are less expensive. Unfortunately the one I ate it did not agree with me. The further you go away from the Via Veneto, the cheaper the prices will generally be. ProfChiara