If Looking for Fine Smaller Less Expensive Hotel
If you're saving money to buy "lembrancas do Rio" (souvenirs) and do not need luxury accomodations, then the Arpoador Inn at the very tip of Ipanema Beach (known as Arpoador) is the place for you.
All rooms are air-conditioned and this is the ONLY hotel located right on the beach. No crossing the street to reach the sand! The remodeled restaurant also looks directly onto the beach sidewalk. The rooms are comfortable and all have a "frigo-bar," a fully loaded refrigerator. I've stayed there twice, and I've only encountered twin beds with very thin mattresses. Many American School alumni stayed there, and all reportedly loved the hotel and its location. Sandbars make great swimming areas for little kids in front of the hotel.
Unique Quality: Around the corner is the Hippie Fair on Sundays, and you're centrally located to shopping in Ipanema and Copacabana. A mere walk from Leblon, too. Only about six stories high, beach front rooms give the feeling of sleeping right on the sand. A grocery store is located around the corner and down the street near the Hippie Fair; conveniently located for buying munchies for your room.
I am not sure about current prices, and I think the hotel was recently remodeled in 2000. Nevertheless, it is probably still very reasonably priced, and only a few hundred yards away from the Ceasar Park Hotel, where Madonna stayed on her Rio tour. Security is the best in Rio directly in front of the Ceasar Park Hotel.
Note: the following comment DOES NOT relate to the Arpoador Inn. Remember, there are hotels everywhere in Rio. You can always find a tremendous bargain if you are willing to stay a block or so from the beach. Just my opinion, but I believe you can find cheaper prices at many places if you just show up off the street. Then again, you just might end up in a nice hotel frequented by lots of prostitutes, as my father once discovered after our family of eight checked in to what otherwise looked like a nice hotel in Ouro Preto, Brazil. Nice place, though.