Until last month I would have said for hard sided polycarbonate luggage Rimowa hands down. I have 4 pcs and have been using them since 2007 with no problem. WF crushed a corner of my carry on so they paid out, with what they paid I bought a Car Friedrik Carry-on, it's a better built, better looking, cheaper alternative to the Rimowa suitcases I've been using.

Every so often I look at buying an aluminium carry on, Rimowa was going to be what I would buy but since the LVMH takeover they're become far too expensive for what you get. On the cheaper side you get more bang for your buck with the Travelite Next, at the same price the Tumi 19 Degrees is super sexy and if you really have cash burning a hole in your pocket the Sterling Pacific Carry On is the one to buy IMO.