If you want to pay a good price and stay in a very decent hotel, Sheraton is your place. Do not expect a 5 star treatment from the staff (that will struggle to speak in english with you), but they try to be kind all the time. Rooms are very spacious and the restaurant is nice. By the time I was there, the President of Brazil (Ms. Dilma) and her staff were all in the hotel - which obliged us to face a huge security screening before entering the hotel.
Negative aspect: there is nothing to do on walking distances. You will have to take a cab to go to the old town, which will take around 15 minutes if the traffic is ok.