If your travels will mostly take you through airports and hotel lobbies, the Hovercraft line of lightweight wheeled suitcases from Eagle Creek are a great bet.
As I said in the rolling carry-on bags report, wheels are not your friend when you are traveling light. If you're checking a bag (hopefully with an airline that doesn't sock it to you with extra fees), it doesn't matter so much. I still see 5-foot-tall women struggling with a 50-pound suitcase nearly every time I go to the airport though, and it's not pretty. If you're going to use a bag with wheels, at least get one that doesn't weigh 12 pounds before you even put anything inside it.
The Hovercraft series from Eagle Creek does a superb job of combining light weight and rugged construction. I've used the Hovercraft 22 version on five trips now (4 domestic, one international) and after a wipedown it still looks new. It only weighs 7 pounds, 6 ounces, which is pretty good for anything rugged of this size with wheels. The wheels are big ones though and make it easy to maneuver. The telescoping handle works smoothly and zips away behind a flap.
There are some nice touches to this bag, including a soft handle on both the top and side, a slide-out luggage tag, a reflective strip to be seen at night, compression straps, and a quick clip to attach another bag. It feels easy to manage when carried, but has a capacity of 2925 cubic inches (48 liters). It can go into expansion mode and hold more if you need to do souvenir or duty-free bottle stuffing on the way home. If you want to see the full specs, you can get them at this page on the Eagle Creek site.
As you can tell from the second picture, the manufacturer would love it if you used this suitcase in conjunction with their packing cubes. If you're the packing cube type, you'll find the pockets and dimensions match up well.
While I prefer to carry on a bag with no wheels in most circumstances, when I'm just going to one hotel for a conference or vacation and it's a direct flight, this is my go-to bag.
Get the Hovercraft 22 at Amazon