The DaKine Fall Line Double is likely the most used ski bag out there, why? Good sizes, good colors, it's durable, has great wheels that are properly protected, and won't blow out hopping up the gutter outside the airport. Big enough to fit 2 pairs of Skis, 1 pair of boots and plenty of gear in but not so big you'll be paying excess weight charges and it's pretty lightweight for a ski bag at 2.8kgs so it doesn't take up too much of your allowance. This is THE bag to travel the world with.
The DakineFall Line Double is made from durable 600D polyester fabric and has a thick layer of padding to protect your planks.