eqblues, that's amazing that you could drop a shuffle hard enough to dent it, given the light weight and the durability of the aluminum casing. Hey, had you been using a skin, the skin might have gotten scuffed up. Maybe you should get a skin protector too.
Haha, just kidding, but my point is the Shuffle is not an expensive fragile thing that might become ugly or damaged by dropping it. I bet only your girlfriend gets close enough to even see that dent.
The only time I dropped an iPod really hard was a iPod photo, which had been dead for over two years. The impact started it working again and didn't cause a scratch!
I never use cases, I feel like they get in the way. I did put some film over the screens of my iPods that have screens.
As you say, to each his own. If you want one, fine, but I think a case on a shuffle will degrade the appearance, add bulk, and make the operation of the unit more difficult.
I bet your Shuffle even with a dent looks better than a Shuffle in a rubber prophylactic, don't worry about it. The Shuffle is a little too cute to start with. You can't make it look ugly by dropping it. You can only make it ugly by putting something ugly on it. Consider the alloy casing to have done it's job of protecting the electronics.