per a friend who is a food writer in SF:
"southern italian I'd say Via Veneto on Fillmore and Clay. Kind of near Pacific Heights. SPQR, also on Fillmore is supposed to be pretty good. I've been to the one in Manhattan and it was wonderful.
http://www.spqrsf.com/. Delfina on 18th in the mission is pretty good but it's packed every night."
She also avoids North Beach.
I'd rather go to New Eritrea in the Sunset though...but that isn't italian food