Gig Bags?
What's WRONG with Gig Bags?
Nothing.
That is if you always remember you're carrying your instrument in a bag:

I have one of these for my D-28:
It serves me just fine to go to a friend's house to play some tunes, but I'll be sure to take my hardshell case if I travel any farther.

Forget it's just a bag, and dump a suitcase on top, and you get this:
Chipboard Cases
Hardshell Cases
Styrofoam Cases
Molded Cases
Flight Cases
Case Covers
