I've read that Zimmerli, the Swiss underwear brand, is one of the best. I once bought a $100 pair of boxer briefs for a friend's birthday off of Mr. Porter, which you can link to here.
(1) Why is Zimmerli so expensive? What justifies it?
(2) I've had experience with Sunspel under garments, which are fantastic. I have yet to buy Derek Rose pyjamas, which I've also read a lot about in terms of their high quality. I'd like to know if the community could weigh in on the finest undergarments (i.e. undershirts, pyjamas, undies). Anybody have experience with the finest undergarment brands and why they're awesome?
I've always said that, since underwear is constantly pressed against the skin, the textile quality should be a top-ranking concern. Would love to learn from SF peeps who know more about this than I do.