I have the official PW case from Amazon--it's not cheap at $40 but does provide quite a bit of protection. After using the official case for a few months I decided I wanted something lighter weight so I bought the Fintie smart shell. While I like the weight of the case, I have to say it doesn't seem like it would provide much protection. So recently I bought a third case for my PW--the Fintie Blade X1. I find it to be a good compromise--fairly cheap at $14 from Amazon, better protection than the Fintie Smart Shell, but not quite as heavy as the official case. I do have to say that the official case definitely provides the best protection. Now of course cases will help, but there are no guaranties when in the hands of an 11 year old!
Here's a link to the Fintie Blade X1 at Amazon:
http://www.amazon.com/Fintie-Kindle-...eywords=fintie