Whichever ones hurt the least. Currently my $6 formerly-white sneakers. They are too filthy to photograph, but they don't even hurt a little bit!

(Yes, my feet and I have issues. I have to wear orthotics, so first shoes have to fit both the orthotic AND my foot in them. No sandles, because the orthotics would fall out. Next, the shoes have to not fall off when I walk, and seeing as I have feet that are wiiiiide at the front, and way-narrow at the heel, this is also a problem. I have a very poor sense of balance (only half - literally - of what a normal person has) so that would rule out heels even if anything higher than an inch didn't cause the orthotics to fall forward and hurt like heck. I do not like shopping, for the most part, but hate shoe-shopping most of all. My mother used to say she would glady pay someone to take my sister and I shoe-shopping, so she didn't have to endure it.)