Once in my life I'd like to sleep in a pair of 150 dollar pajamas. These by Marni for H&M (I'm surprised the stores aren't covered in drool over this collection) are on my totally-impractical-but-really-don't-care list. Sold as a blouse and shorts, there's no way I'd only wear these for day time.
Finally I can justify sleeping in something, then keeping it on the very next day. Wear and repeat.