Rua Treze de maio, 634 Bixiga / Bela Vista - (11) 3288 2573 /3284 2987
http://www.cantinaroperto.com.br/
Croweded, loud and serves pasta! =P
I´m not the biggest fan of the Italian food, but this place is quite tradicional.
Price is not cheap, but we had a good meal.
Bixiga is the tradicional old Italian spot in town, and on sundays they have an antique open market near the restaurant, might be fun to look around.