When travelling to Brazil, you’ll probably at some point consider the fact that you’ll have to charge your electrical devices, and you’ll wonder about the outlets – will you be able to plug everything in? Unfortunately, this is not an easy answer. Because, in Brazil, they have three different types of outlets (not counting the large-device plugs for fridges, air conditioners, etc.).
The first outlets are actually the North American standard – these are more common in older areas, but Brazil changed outlet type a couple times.

The second type are probably the least common, but could be easily made backwards adaptable so that new devices could use prior plugs with minor modifications – this way people didn’t need adapters for their day-to-do.

The third type are no doubt the safest – they are the only properly grounded outlets, and the outlets themselves are slightly recessed so as to avoid that short period when both the metal is exposed and the electricity is still flowing. It also helps reduce the chance of sparks when plugging/unplugging a device, as the spark is better contained in the plastic cover.
So, if you are wondering what adapter to buy before travelling to Brazil, the answer is “don’t.” Buy an adapter after checking into your hotel and determining which type of outlet you need – it varies too much right now, and even Minha Namorada carries an adapter with her so that she can use outlets wherever she goes. This also has the added benefit of being cheaper, since there isn’t enough demand in Canada to make Brazilian Adapters profitable, you’d have to buy a high-end universal adapter here to ensure it covers Brazil, whereas you can get them cheap at the hotel in Brazil, or even cheaper at a local mall.