Speck's FitFolio is one of our favorite iPad and e-reader cases, and now it's available for the Kindle Fire. What's nice about it is that the device fits securely in the form-fit hard shell case, and your screen is protected by a "vegan" leatherette book-style cover that folds back and converts into a stand (yes, vegan leather means faux leather). A small bungee cord keeps the cover closed.
This one comes in black, red, and teal for $34.95. Speck also makes the $29.95 BookWrap (it does not convert into a stand) and soon-to-be-released WanderFolio for Kindle Fire, which is similar to the FitFolio but incorporates some hideaway pockets for "cards, cash, and more" in the cover.