I have used iwantpants for a number of years. They remain the best place to buy men's underwear online in the UK. They stock all the current (and future) trends in underwear. I consider them somewhat of a vanguard and a source of inspiration for men's underwear. They are a breath of fresh air in what is often seen as a rather dull and drab market.
My only criticism is that during sales and busy periods they can be slow to respond to emails, but they make up for it by being accommodating and providing excellent value for money.
To reply as a company, please log in to your business account.