If you want a tough little carry-on suitcase that will stand up to absolutely everything you throw at it then go for an Eastpak Tranverz XS. Not double decker like the larger Tranverz ones. Only 28.5 litres. This beige camo print called Safari (I can't get the right picture on screen) won't suit everyone but it's half the rrp and cheapest I've seen for ages. Includes £7.99 postage.