I grew up in northern Italy and Il Borgo is my absolute favorite Italian restaurant in SF. Its homey vibe reminds me of the little trattorias in Italy. The menu has something for everyone - primi, secondi, salads, desserts. I've been going to Il Borgo for years now and the waitress always makes me feel at home. The pastas are homemade and delicious. I've tasted a number of things on the menu and my favorites are the gnocchi, spaghetti carbonara (the most authentic I've found in SF), the insalata al'Borgo, and the chicken saltimbocca. Order a glass of the house wine, relax, and pretend you're in a cozy trattoria on a quiet side street in Venice. Note: It is cash only, but there's an ATM in the restaurant.
Pros: amazing food, cozy atmosphere