I got these classic white full-cut briefs from, of all places :-), a upscale department store called Nordstrom. These are their store brand briefs and come in a 3-pack. They are appropriately sized in even numbers from 32 on up.
They are 100% cotton. I supposed I could say in terms of quality they are on the order of Calvin Klein, but they are cut different (a bit more material on the hips perhaps?). These also have a wider waistband, which is nice.
Anyway, not a bad addition to my collection. Though I bought them well over a year ago, I’ve only wore them less than a handful of times.