Our first three nights were a near disaster at one of Rio's so-rated "five star" hotels. We moved to the Porto Bay by chance and could not have been happier. Unlike some of the other bigger hotel names, the Porto Bay is exactly what it says it is.
Nothing in Rio (nor much of Brazil) is cheap so never expect great value for money. But this hotel made us very happy and was reasonable value for money. Nice clean and spacious rooms, with a decent breakfast to keep you going until the afternoon. The rooftop pool, with a beer of caipirinha in hand, at the end of a long day in the sun, gives you amazing views over Copacabana Beach. The pool is not for swimming but great for relaxing and cooling off.
When we wanted to get out of Rio for a few days, the front desk gave us a number of recommendations and helped organise transport and accommodation. And was done with a smile. And we ended up choosing another Porto Bay hotel based on the quality of this one (local staff did not even suggest it).
I will head back to the hotel next trip.