I've got to admit, I'm only comfortable with used clothes from people I know. But part of the reason I can afford to be picky like that is that I pick up most of my kids' clothes from clearance sales the year before. That way they're new but only cost a little more than second hand.
I consign our used things and work at a consignment sale twice a year, and sometimes I find brand new things there with the tags still attached. Those I buy with no hesitation.