I've never been to any of the cities you listed in the North East outside of Recife, but I've been to the rest.
I would choose Rio, but I'm biased towards tier 1 cities (against the convential wisdom of RVF) because I like having access to all the amenities that a tier 1 city offers. The downsides of Rio are it's the most expensive, but you'll get by at $2k per month as long as you eat most of your meals at home and don't party more than 2-3x per week, and the carioca accent is ugliest in all of Brazil so make sure you're português teacher is not a local.
Floripa is great but logistics are a bitch if you don't have a car and it will be dead the first 3 months you are there.
Porto Alegre has good bbq and beautiful women, but other than that I found the city rather dull.
Generalizing about the NE your dollar will go farther, the women will be easier (and uglier), and the cities will be backwards shitholes outside of a few nice spots.
I would choose Rio, but I'm biased towards tier 1 cities (against the convential wisdom of RVF) because I like having access to all the amenities that a tier 1 city offers. The downsides of Rio are it's the most expensive, but you'll get by at $2k per month as long as you eat most of your meals at home and don't party more than 2-3x per week, and the carioca accent is ugliest in all of Brazil so make sure you're português teacher is not a local.
Floripa is great but logistics are a bitch if you don't have a car and it will be dead the first 3 months you are there.
Porto Alegre has good bbq and beautiful women, but other than that I found the city rather dull.
Generalizing about the NE your dollar will go farther, the women will be easier (and uglier), and the cities will be backwards shitholes outside of a few nice spots.