The free cardboard boxes that bikes come in are a good option if you're taking your bike on an airplane. But it's like taking your MTB kit in a carrier bag - practical but totally lacking in purposeful style.
This Merida bag is still going strong after several flights and a summer of lounging under a pile of wheels in a filthy garage. A stiff base and slot-in plastic panel structure make it more damage-resistant than many bags.
Four tough wheels make transport easy and there's loads of scuff protection on the edges. Internal padding, separate wheel sections and pockets for storing removable parts all add to its appeal.