I travel carry-on. The only time I check anything is if the flight is nonstop and the airline is so small there isn't enough room for my little international bag or only one bag is allowed in the cabin. That typically means intra-European flights or ones using smaller US planes that require gate-checking.
My criteria for luggage is in this order: size, weight, style and price. Brand isn't an issue and I'll consider anything that meets those criteria. Having said that, from my closet list below it's obvious that Eagle Creek, Lipault, Baggallini, Rick Steves and Eddie Bauer are favorites.
I have only soft-sided bags. I have yet to find a hard-sided bag that isn't too heavy -- especially by comparison to soft-sided bags. I have one 4-wheeled bag, two 2-wheeled ones and a couple of backpacks. I like all of them for different purposes.
So this is what's in my closet, in order of what I use the most with the piece at the end that I hope to use in the future.
Eagle Creek International carry-on. It's expandable, but even expanded it's still small. 20.25" x 14" x 8"-9.25", 36-39 L, 4 lbs, 9 oz. Interior bottom 13" x 6", top 14" x 5", middle 14" x 6". Mine is an older and a slightly smaller and lighter version of this bag.
Eagle Creek Load Warrior Wheeled Duffel 22. I use this when I want something a little bigger. It has to be checked on any airline if I expand it. 22" x 14" x 9"- 11". 41-45L. 5 lbs, 8 oz. Interior 14" x 7" except 14" x 6" at the top. Eagle Creek no longer makes anything quite like this with the U-shaped handle and only 2 wheels.
Lipault Plume spinner. Not expandable. I don't use this bag much anymore, mostly due to its larger size. It's still in great shape, even after several domestic trips and overseas ones involving cobblestones. Overall Dimensions: 21.6" x 14.9" x 9.4". Interior dimensions 20.6" x 13.2" x 7.9". 45L. 6 lbs. The newer ones are lighter than mine.
In the past I've used cross-body bags like this as my personal carry-on item. On my last trip in the summer of 2019, I found my cross-body bag very uncomfortable on my shoulder and neck with the weight I had in it.
I think next trip I'll try one of the backpacks below as my personal item instead, IF they meet the airline's personal item sizing requirements. Either will fit under the seat in front of me and accommodate the things I normally need during a flight, including the typical little cross-body purse like this one I got in green for the 2020 Ireland trip that didn’t happen.
Appenzell Day Pack. 22.9 L. 18" x 13" x 6.5". 1 lb, 6 oz. I've used this Rick Steves backpack for domestic trips, but not for anything overseas yet. With my back torso length of 17" - 18" and its design and construction, I find it very comfortable.
Eddie Bauer Stowaway packable daypack. I haven't used this new bag yet. 20L. 11 oz, 18" x 10" x 9". (8.5" x 7" x 1.5" stowed). If I use this one it won't be stowed.