Uppercase Ultra Thin Keyboard Cover
It isn't a case, but the UPPERCASE Ultra thin keyboard cover will protect your keys unlike anything else. You know what we mean. When those black MBP keys start to get shiny and wear out from days and days of typing. Not only will this protect and prolong your keyboard, but it should save it in the unlikely event of a spilled cup of coffee. Made of a rubberized TPU material it wont melt or show wear and tear. I have this exact model on my 13-inch Retina and it's a perfect fit.
$12.99 at Amazon