I'm a big fan of the M-Edge covers. Right now my primary reading device is the K3, and I'm using the
Icon Sleeve for it. It's great for on-the-go, protects the device, and it isn't cumbersome because it's not a cover that I have to try to fold back and hold (which I've found is an issue for me with the really light devices). I've also used the Icon Jacket and the GO! Jacket and loved both.
My goal in having a cover is:
1. protect the device
2. style!
The second point is why I'm willing to pay $30-50 for a decent case. I want to spruce it up a bit, give it some color and personality