Brazil is definitely too big for the majority of single trips. I spent lovely time there (twice), but didn’t have enough time to explore as much as I’d like to.
I hope to have a chance to go to Brazil once more, then a few national parks are going to be on my list (e.g., Lençóis Maranhenses, Aparados da Serra, Serra da Bodoquena, Pantanal Matogrossense, Chapada dos Veadeiro, and Fernando de Noronha).