Wii U GamePad Silicone Protector
Go For it.
No real reason NOT to get something like this. It has protected my game pad very well. I am yet to drop it but I think that Nintendo built the game pad well enough that it can sustain a lot... I've kind of looked into it. But anyway, this sleeve is comfortable, barely noticeable, easy to apply, easy to take off. It doesn't interrupt game play or charging in any sort of way. Really a no brainer that you should pick either this or something like this to protect your beloved Wii U.