Hello OP,
Rio de Janeiro is most spectacular cities I've seen in this world. It's physically stunning. I don't speak a word of Portuguese, but everywhere I travel I do learn how to say "please," "thank you," "good morning," and "are you sure your wife is away for two hours?"
Go to Rio. If you want the hotel to stay at, then I highly recommend the Copacabana Palace Hotel.
There are three major sections to Rio: Ipanema, Copacabana, and Centro. The latter is the downtown. Stay in Ipamema or Copacabana. If you can stay along the beach.
If you like art, on Saturday (I think it's Saturday) nights, they have local artists sell all their work and it's dirt cheap.
I bought 12 piece set of Portuguese china for around $350 -- and it's well made china in Rio Sul shopping center.
Go to Rio!
David