I wanted a cover that didn't weigh too much, had magnets for the automatic on feature, didn't cost $40, and didn't have a flap to get in the way. I ended up with a
Fintie Navy Blue case, which has been great so far. I worry that the bottom of the "spine" will wear out eventually (I still hold it there sometimes) but if it does perhaps there'll be an even nicer reader out by then. If not and I wind up buying another cover, I'll still be ahead.
If I were to buy an overly fancy cover it'd probably be something like this
Neverending Story cover. :)