Don: Rosalie and I have eaten twice at Trattoria Al Moro, about a half block from the Trevi Fountain. It was highly recommended, and we agree. Best Amatriciana sauce in the city, good grilled seafood, impressive wine list, arrogant and snooty service, especially to Americans, but the food makes up for it. Good atmoshpere, but the seating is tight and pretty packed in. Address: Vicolo delle Bollette, 13, Roma. (The fact that the adjacent street, leading up to the Trevi Fountain, is Via Poli does not affect my perception of the place...)
If you get to Trastevere (sort of the Shadyside of Rome), there is a place called cafe Da Enzo, and we have eaten there twice, as well. We stumbled on it the first time Rosalie showed me the Trastevere, and it was the first restaurant we saw. Small place, no tourists, people eating outside. The food looked fabulous. But we couldn't stop at the first place we saw, so we walked around for a couple of hours, but ended up back at Da Enzo, having found nothing that looked as good. Here is a link:
http://www.whatihadfordinnertonight.com/?p=4205