After many years of buying Tumi and Hartman, I've switched to Briggs & Reilly. It is well designed and has a life time "no questions asked" guarantee. I haven't had to send any back for repairs yet, but the tag says that they will repair any damage, even if the airline causes it.

My favorite Briggs and Riley carry-on is a small garment bag that is shaped like an ordinary 21" carryon because the fold is on the side, rather than on the top, like most garment bags. I travel on business and I can fit in all the clothes and other stuff that I need for a two day business trip with no problem. (That may not seem like a big deal, but for a woman, believe me, it is.)