Madonna can sing all she wants about being a "material girl," which to me is all about having more stuff. I'm a functional girl. First and foremost, I want something that works well. If it doesn't, I'll keep looking for something better. And I want less stuff that serves more functions.
I'm waiting for the large zip-out shopper bag from Baggalini to become available. It's 18x22x7, ripstop nylon, can be checked as baggage on a plane, zips into its own little pouch and weighs less than a pound. It's big enough to carry the few items I need for an overnight trip, or on longer trips I can throw it in my suitcase and use it to carry my dirty laundry to the laundromat.
Lots of functionality--it works for me.