Haven't been to these except for Pizzeria Paradiso. Heard great things about Obelisk and Laboratorio del Galileo. From the Washingtonian:
From Washingtonian's best bargain restaurants - Italian.
A LA LUCIA Alexandria, 703-836-5123 moderate
CAFE MONTI Alexandria, 703-370-3632 inexpensive
CAFE TIROLO Arlington, 703-528-7809 inexpensive
COPPI'S ORGANIC U Street, 202-319-7773 inexpensive
DOUGHBOYS Gaithersburg, 301-330-3212 inexpensive
LA PIAZZA Alexandria, 703-519-7711 inexpensive
MARCELLA'S Chevy Chase, 301-951-1818 inexpensive
OLAZZO Bethesda, 301-654-9496 inexpensive
PASTA PLUS Laurel, 301-498-7878 inexpensive
PIZZERIA PARADISO Dupont Circle, 202-223-1245 moderate
Georgetown, 202-337-1245
SETTE OSTERIA Dupont Circle, 202-483-3070 moderate
SORRISO Cleveland Park, 202-537-4800 moderate
http://www.washingtonian.com/dining/bbcuisine.html#Italian
From the Very Best Restaurants - Washingtonian:
1-1/2 stars
A LA LUCIA Alexandria, 703-836-5123 moderate
2-1/2 stars
AMICI MIEI Rockville, 301-545-0966 moderate
2-1/2 stars
GALILEO Foggy Bottom, 202-293-7191 expensive
4 stars
LABORATORIO DEL GALILEO Foggy Bottom, 202-293-7191 v. expensive
4 stars
MAESTRO McLean, 703-821-1515 v. expensive
2-1/2 stars
NOTTI BIANCHE Foggy Bottom, 202-298-8085 expensive
3 stars
OBELISK Dupont Circle, 202-872-1180 v. expensive
3 stars
PALENA CAFE Cleveland Park, 202-537-9250 moderate
2 stars
PIZZERIA PARADISO Dupont Circle, 202-223-1245 moderate
Georgetown, 202-337-1245 2-1/2 stars
RISTORANTE TOSCA Downtown, 202-367-1990 v. expensive
http://www.washingtonian.com/dining/vbcuisine.html#Italian