I like dark grey. It doesn't show scuffs or normal wear & tear, and is distinguishable from the zillions of black bags sliding out on the carousel. I have a several-years-old Skyway set that is sturdy and still looks new, even after numerous trips. Since one can never have enough luggage (DH rolling eyes), I'm thinking about a new couple of pieces in grey.

I have some red luggage and it used to be fairly rare. Now lots of people have red. Plus it really shows those gorilla handler marks.