I'll also pretty much second everything Linda said.

I'm not sure which pair of the Gore shorts I have, but they seem awfully snug in the legs and have (oddly for me) a little too much room in the butt. I can pull them up ridiculously high in the back. (I understand that's to prevent plumbers crack, but if the front pulled up as high as the back I could wear them at my bra, and I have a long torso). And the chamois seems...large. And it's sort of difficult to arrange the shorts so that the chamois is snug.

I bought a medium, but wear a 2-4 in normal pants.