I sleep naked, so I do not really wear anything at home.
But if you ask, what is the "most comfortable underwear"? I would say that
in my personal opinion, 1) silk boxer, and 2) Ergowear X3D series.
Silk really has its unparalleled sleek quality and it is so light and thin.
And amazingly, silk keeps you warm in the winter and cool in the summer.
No wonder that Chinese and Roman royal members wore silk.
I do agree with member b.c. that Ergowear, particulary the X3D-shaped, microfiber textile, is THE most comfortable underwear I have known. Their very soft textile makes the extra-large pouch hug and support your boys but not pressing too much. Your boy has enough room to stretch. I freeball a lot, but when I have to put on underwear, ergowear is often my choice. I like CK, 2(x)ist, and Unico too. A friend introduced me to an European brand "Skipper," very very thin cotton underwear, very interesting!