My favourite city in Brazil is Curitiba - PR. It's a very nice city, there are lots of Shoppings, parklands, public areas, nice places to visit like Oscar Niemayer Museum, a very extensive list of places to go!
I'm from Santo André/SP, but I hate living here, I would to live Region of Americana/SP, It's countryside of Sao Paulo State's, Because is very quieter than Santo André,the climate is hottest, Because I love being near of nature. There are others cities that I would like to live like Goiania, Florianopolis and Curitiba. I have never been those places, But my friends that already been there told me that are good place for you live.
I'm one of the few gringos who actually prefer São Paulo over the cities at the coast. I think every city in Brazil attracts a different type of foreigner... the surfers go to Floripa, the party people go to Rio, beach lovers hang out in the North East and those of us who want to study or be productive in some way go to Sampa... so it depends! But I've been all over and I've really enjoyed most places I went in Brazil. Deus é brasileiro.