Top Case 4-in-1 Bundle
Top Case, like Speck and others has a somewhat durable hard shell case, but that isn't all they offer. For someone looking for one purchase the Top Case four-in-one bundle has almost everything you need to protect a Macbook Pro Retina. A hard shell see-through case, color-matched sleeve, silicon keyboard cover (also color-matched) and an HD screen protector you may or may not use. It's a great package for a good price, and comes in over 10 colors.
$24.99 from Amazon