Sorry, but I don't peek in here often so just saw your post. Among my favorites in Rome for dining...
Osteria Il Gladiatore, Piazzale del Colosseo 15 (near the ancient city): Traditional Roman dishes. Reasonable prices. Try to sit outdoors if the weather is good.
La Rosetta: On the small street of the same name. (Not far from the Pantheon). One of the city's most popular and best fish restaurants. Simple, Sicilian food,. Try especially the pasta with sardines grapes or fennel. Be sure to drink the Corvo wine that is served in carafes. Reasonable prices.
L'Orso Ottanta, via dell'Orso 33 (near the Piazza Navona). One of the great antipasto tables in the city, also for pasta dishes and meat courses. Personally, I always feast here on antipasto and then a pizza. Reasonable prices.
Dal Bolognese, piazza del Popolo: Specializes in Bolognese cuisine. Try especially the bollito misto (boiled meats with green parsley sauce, capers and onions). Reasonable prices Reservations suggested. Telephone 679-20-83.
Osteria Marcello, via Aurora 37 (near the Via Veneto): Good food despite being a very "in" restaurant. Try the brasato (pot roast simmered in wine), and any of the pasta-vegetable combinations. Moderate prices.