Not a true one-bagger due to being on-call 24/7 and carrying two laptops (and more) for my office, and sometimes getting sent to far-away places mid trip. Sometimes I get sent to 3rd world countries with frequent extended power outages <cough>California<cough> and questionable water supplies, so I carry enough supplies to keep me self-sufficient for at least 7 days.

Ignoring the work stuff, I use a Costco 2-wheeled carry-on has been my travel companion since 2008 when I became a Costco member. I can get away with it for a week if need be. Rolling clothing + packing cubes have made a world of difference. Nothing fancy on the packing cubes, just a few I've picked up from Amazon over the years.