So far these Adidas athletic briefs have provided me with a snug and comfortable fit while playing tennis, jogging and just walking around the city. But it's not so much what they DO, as what they DON'T DO: 1) They stay in place, never riding up my thighs, even when I'm lunging, twisting and bending. 2) The waistband never digs into my waist, even when I've put on a few extra pounds.
My hunch is that the great fit and feel of the briefs has to do with two factors. First, the briefs have a good shape to them, a good cut, if you will. Second, the material -- 91% Polyester and 9% Spandex -- seems to provide a good level of elasticity and form, which in tandem with the cut of the briefs gives a good, snug fit, but without riding or bunching up in any spots.
Another agreeable aspect to these briefs is that they are super lightweight and feel cool on even the hottest days. And best of all, they come in a 2 pack. I think they're a bargain at this price point.
I am 6'1 & 185 lbs with a 33/34 waist. I purchased the Size Large and they fit me great.