Briggs and Riley computer-roller type bags for me. I still think the B&R KR250X is the best looking and serviceable even though it is a couple of iterations old now. Like Global Adventurer above, I carry a cheap canvas-type foldup to put the B&R inside of in case I ever have to unexpectedly gate-check it.
As for checked bags, I don't care about brand so long as they are somewhat hardsided and offer protection. I sort of expect them to get beat up so I don't have any particular feeling for the bag itself unlike my computer-roller.