Attached my recommendations for going out in Sao Paulo. No guarantee is given regarding its up-to-dateness, as places open and shut down in Sao Paulo quite fast, but these were the places which I enjoyed a lot when I was in Sao Paulo in Sep08-Feb 09
Bar Aurora (Attilio Innocenti) : good place to have a couple of Beers, used to be great on Sunday evenings, people then however moved to the Bellini, which however got shut. On Tuesdays particularly good singer
Azucar (Mario Ferraz): Good Salsa bar, have salsa lessons, crowd 30+
Boteca Ferraz (Mario Ferraz): Same owners as the Bar Aurora. Great place, great beer, but mediocre kitchen
Salve Jorge (Aspicuelta): Legendary place, a good place to start an evening in the Rua Aspicuelta in Vila Madalena
Sao Bento (Aspicuelta): The Sao Bento in Vila Madalena is also an excellent place to start an evening.
Sao Bento (Joao Cachoeira): When looking for a quick beer after working in Itaim, the Sao Bento in the Joao Cachoeira is probably a safe bet and a very open place.
Hamburgeria Nacional (Leopoldo): Probably the best Hamburgeria in town. Delicious meat and sizable portions. A little upscale in terms of pricing.
HSBC Belas Artes (Consolacao): Cinema with rather alternative movies, contributing to the reputation of Sao Paolo as a center of filmatography
Cafe Santo Grao (Oscar Freire 413): Clearly the best Cafe in Sao Paolo. the 20 % price premium when compared to the Suplicy is definitely worth it. Comfortable armchairs, free internet (within a time limit) and a very central location make it a must see for the coffee lover.
Suplice (Lorena): Good Cafe, but no match for the Santo Grao (or the Otavio in the Faria Lima).
Devassa (Lorena): Great Beer in this bar, the bottle is definitely one of the potential takeaways. Food leaves some room for improvement.
Anhanguera (Aspicuelta): Fantastic beer choice from all the German-Origin Beer breweries around Brazil. Packed on Friday and Saturday evenings, but worth the wait.
Zeppelin (Aspicuelta): Nice bar to sit down and have a long conversation, definitely one of the potential stops in the Rua Aspicuelta.
O do Borogodo (Horacio Lane): After warming up in Vila Madalena with a few choppes at the wide variety of bars available this is the place to go to if you then want to show off or learn some samba. From the outside it really looks like a hole, which in all honesty it is, but what a hole ! Great atmosphere.
Connexao Caribe: If you are more into the Salsa rythm rather than the Samba, this is the place to go to. Popular with the Exchange student crowd of USP.
Bar Maevva: Good Happy hours within itaim, often live bands. Great when you are in it, really bad when you are in a room of the back side of the Blue Tree Faria Lima hotel trying to get some rest.
Rey Castro: Truly great place, generally good band and good beer. Great atmosphere, although a little stylish and pricey to be a true heir of its name-sponsor. Relatively safe bet for a great night out.
Ali Barbar: Place with a slightly Arabic touch. Try the other recommendations first before going here.
Charles Edwards and Dublin: Good Pubs with (expensive) European beer, although both mostly known as meat markets for the age bracket 35plus.
The View (Santos): Great view of Sao Paulo, good piano music, really romantic with moonshine, but definitely also a hefty pricetag.
Lellies: Great Pasta - the one in the Bela Cintra is better.
Not so great
Figa Bar: Rude personel literally insulting guests, overpriced, inaccurate billing (covers added despite specific answer that no cover was applied before entry of restaurant), something I never encountered before... ever !
Trianon Piano Bar: Again overpriced, not great Ambiente