Normally, I go to Paris at least four times a year to show our new lines of women's and men's clothes, and I have a favorite store that I would personally visit every time: the first store of the female fashion designer agnès b. on the Rue du Jour in Les Halles.
Not too many people may know, but I love the black long-sleeved T-shirts she designed. The fabric is thick and sturdy, so it does not stretch no matter how many times it goes through the washing machine.