Default Poetic Revolution for the HD 7.

I received mine last week and this is the best case I have found that offers drop protection, a built in stand and screen protector. The build quality is on par with Otterbox, Gumdrop and Trident. It fits well and so far has passed the 4 year old test with my son. I can't post links because I only lurk on the forums, but you can find it on amazon for $30 with prime shipping.

Product Features
A state-of-the-art revolving stand, allowing for multiple viewing options.
A loop hole for an optional carabiner, in case you wanted to attach the device to your clothing or backpack.
Made with PC and silicone, the flexible textured material allows for great grip, slip-resistance, and impact resistance,
The Revolution features a touch-sensitive, water-resistant screen-guard.
Additional functions include a flip-out stand for easy typing position, dust prevention and port protection.