Unless you count the gown I wore to a presidential inaugural ball, the least practical item I own is a top that is quite hard to describe. The base layer of it is basically a corset, and over that is a very floaty slightly sheer layer that drapes over the shoulders and is cinched at the waist with a ribbon belt. I think of it as the closest I will ever get to dressing like Carrie Bradshaw. It's really pretty cool, kind of goddessy, but I wore it for a very special evening of surprises for my 40th birthday in NYC, so it was perfect.
For the last few years i haven't been able to fit in it, but I think I might be able to wear it again. My husband wants me to wear it again for my birthday this year -- I'm going to try it, but I definitely will not be able to eat a big dinner if I wear it!