22 inch Kirkland from COSTCO. Allowed as carry-on. If you get a job flying long haul, out for 2-4 weeks, get 2 of them and piggyback them. As a former commuter for a supplemental, I gave my luggage a real workout.
On 2 of the 3 occasions I have had to check bags not allowed as carry-on, the airlines lost them. Delta lost a bag of donated baseball equipment for 3 weeks in MIA that I was trying to take to kids in Venezuela. United lost my son's catcher's bag on a non-stop from LAS to DEN. Thank God it was after the Legion regional tournament, not before.
Regardless, I appreciate all the fine folks at DAL and UAL. I just don't check bags with anyone if at all possible.