A nice, comfortable, well-equipped flat really close to Copacabana beach. The area itself has a few bars and restaurants but you have to travel a little for the best places. That's no problem though because there's a metro stop less than 10 mins walk.
This place is great if you want somewhere nice to crash and you're happy to do lots of exploring. But if you want somewhere where you never have to go far from the apartment that's still near the beach, maybe try somewhere in Ipanema instead.
Rafael was really helpful, and answered a bunch of questions for us about how to get around while we were there, even at really short notice. There's a lot of handy info in the flat and he's put together a guide of the best bars/restaurants/clubs too. (Pretty telling that only one of them's in Copacabana though!)