I refuse to buy a 'luxury' design of a product and then stick a $10 piece of plastic on it. So no, I do not skin it. I don't have a case on my iPhone or iPad either for the same reason.
I want to skin the new 15" I bought, but I'm looking to find a skin that's really hard to notice. Most of the ones I see really seem to have some kind of design, which isn't in and of itself bad looking, but I just want something that fights tightly to protect from dust and scratches without altering the look of the device itself much.
You can get different materials beside cheap plastic.