Travel expert Rick Steves gives us this sage advice:

The importance of packing light cannot be overemphasized, but, for your own good, I’ll try. You’ll never meet a traveler who, after five trips, brags: “Every year I pack heavier.” The measure of a good traveler is how light she travels. You can’t travel heavy, happy, and cheap. Pick two.

I can’t stress enough how important it is to travel light.  We will be moving from city to city many times on this trip and that means lugging your suitcase through train stations, into cars and taxis, up and down stairs, into overhead luggage bins, over cobblestone streets, and of course it has to survive the airline baggage handlers.  Believe me, any old rolling suitcase is NOT up for the job.  You need a suitcase that is built with quality parts, lightweight, and intended for heavy travel abuse.  Think of a good suitcase as an investment that will allow you to enjoy your trip without worrying about broken wheels, busted zippers, and ripped seams – all very common problems with average luggage. A quality piece will last a long time through many trips and will pay for itself.

I have an Eagle Creek Switchback bag that I bought in 2001 before mom and I went to Europe. It has survived two three-week trips across Europe, a three-week trip down the Pacific coast, two trips to Orlando, and four months of living out of it with constant travel for my old job. I’d say the $250 I paid for it was an absolute bargain; even if I had only ever used it on the one trip it would still be worth it.  It’s still in good shape and I’ll be taking it on the next trip.

Now lets talk about weight. 50lbs may be the airline weight limit, but you need to think about what you are comfortable carrying. You will not always be able to roll the suitcase, there will be many times when you have to carry it. Pick up an empty suitcase to feel how heavy it is, then imagine how it will feel when you have packed it to the gills. Experienced travelers recommend that your total weight be no more than 25 lbs. That goal can be difficult to reach; you have to plan carefully to travel that light.  The easiest way to reach that goal without leaving behind clothes or shoes is to start with a lightweight suitcase. If you shop for luggage online you can usually look at the product details and see the weight info. I recommend that you plan on a 10-12lbs suitcase. Anything weighing more than that better have a pretty significant selling point to make up for the heaviness.

I researched the following bags and they are a good size, get great reviews, and meet all the criteria for our needs. The link takes you to eBags, a luggage retailer with lots of product data and reviews. You might find these bags cheaper elsewhere, but eBags is a good place to research and decide what to buy.

• Eagle Creek Tarmac 25 – $295
  
• Travelpro WalkAbout Lite 2 30″ Rolling Duffel – $116
• High Sierra 30″ Drop-bottom Wheeled Duffel – $221
• High Sierra Level 28″ Expandable Wheeled Upright – $221

Some of these are classic suitcases, some are duffels. Each has their pros/cons, you need to decide which works best for your style of packing.  None of these are carry-on size, I don’t begin to hope that we could all take carry-on size bags. Also, do not get a bag bigger than 30″, as it will not fit in the baggage area on trains. Really, the smaller the better.

Last, I highly recommend that you read this article about packing from Rick Steves: Packing Light and Right.   Very excellent info that I sincerely hope you take to heart.