If you are looking to play the game without paying a dime, than the Android Market version-supported by ads-is for you. On the other hand, if you have had enough commercialization whether it's YouTube or Angry Birds, the Amazon app store has the exclusive rights to offer an ads-free version of the game. Of course, you would normally have to pay for that privilege, although it is currently free for a limited time as a promotion.
It's not as easy a decision as paper or plastic, but either way, you get the pleasure of playing the highly addictive game. Rio brings 60 new levels of Angry Birds action which means you will be zoning out, holding your smartphone in front of you for quite a few hours.