Remember Brazil is HUGE! If you don't want to spend too much time on the road/in the air, then I'd suggest just focus on a couple of areas.
My suggestion would be Rio (city) for a 4-5 days to start, there's a lot to see and do there, then head out to Rio state for some time - upto a week maybe?
Add a flight to Iguazu Falls for about 4 days - they are spectacular and you should spend a day seeing them from the Argentinian side too.
This would leave with you a few days at the end to take in another place or hang out in Rio some more if you liked it. You could try Sao Paulo but it doesnt have a lot of appeals for tourists. Cities further down the coast on the south could be nice to kick back in.
If you start flying to places like Salvador or Fortaleza or the Amazon you'll spend a lot of your time flying and culturally they are very different places to the south and much poorer too. about 6 years ago
1. Take an overland tour - Intrepid has a good one that gets out as far the Pantanal
2. Take a flying trip - TAM has/had a cheap flying package for international visitors (must be bought outside Brazil), and take in Salvador de Bahia, Fortaleza, Manaus and others. Join a trip into the Amazon (Gero Tours recommended) about 6 years ago
What you like to visit ? Beaches ? Forest ? Big Cities ?
The best beaches was in "Nordeste" Salvador, Natal, Maceio, and Fortaleza if you liike big cities, or Canoa Quebrada, Itacare if you like nature, try this http://www.viajenaviagem.com/brasil/brasil-a-z/ almost 6 years ago
I think it's almost mandatory go to the northeast. Specially Salvador (Bahia), Chapada Diamantina (Bahia), Recife e Olinda (Pernambuco) and maybe Maceió (Alagoas) and Fortaleza (Ceará). It's far more interesting yuan Rio de Janeiro and São Paulo, the usually Cb. sen. By foreing travelers. about 5 years ago
Rio is a must, no matter how much it has been said. 5 days will be nice, dont miss beaches. Try to spend a weekend. If you love soccer, maybe it is a good idea to go to a stadium, but try to find some friend from here to join you. Rich nightlife. Nice nature. Angra dos Reis region is close to Rio, maybe you can take 3 extra days in there, and Ilha Grande is a nice place to stay.
Well, for the other two weeks you need to make choices...Amazon Forest (never been ther, cant tell you how many days you need), Iguazu Falls (two days enough),all cities in the Northeast can take 2 weeks... (Salvador should be your first option but you also have Fortaleza, Jericoacoara, Recife). And if you wish to see marine life, and like to dive, go to Fernando de Noronha Island, the most beautiful place in Brazil. Pantanal and Bonito Region are very nice for those who like adventure. All those places are quite far from each other, and need to get a plane. about 5 years ago