Travel Series: Luggage
I don't think you can start a series on travel without talking about luggage. Everyone has their own system, so you need to travel with what makes you feel comfortable. That being said, I think the luggage I have matches my level of travel without breaking the bank. Personal Item ($15-$20 USD)
In the USA you can travel with one personal item and one carry-on. Not bad, except when you land in London and are limited to one carry-on, no exceptions. (During hightened security levels only.) Then your personal item has to fit inside your carry-on. Additionally, I wanted a bag that I could drop my Asus eeePC into without it screaming that I carried a laptop. So I use a messenger bag similar to this one.
When I travel internationally, I pack my carry-on with enough empty space to slide my messenger bag in, if necessary. That way I don't have to abandon stuff at security checkpoints.
Carry-on ($50-$75 USD)
I use the American Tourister 25" Meridian as my carry-on of choice. I can pack five days of summer/spring clothing into this bag without busting the seams. It fits into the overhead bins, wheels first, so other passengers have room for their stuff. If I have to take along my Sony Vaio, it has an perfectly-sized external pocket.
Check-in ($150 - $250 USD)
I inherited my check-in bag of choice. It is a hard-sided Delsey my family purchased over 20 years ago. This is the same bag that flew off the top of a van going full speed down a highway in Chang Mai, Thailand. The car behind us was kind enough to hit it and push it to the side of the road so we could assess the damage. Aside from a few scrapes, the bag and our belongings were fine. The locks didn't even pop! I love this bag and I use it for all international trips or trips within the USA that are more than 5 days long. I'd post a picture, but Delsey doesn't make that particular brand anymore.
What kind of luggage do you use? Please share your reviews and links in the comments.