There is a GREAT selection of high-end goods at the FB (Filene's Basement) on Connecticut Avenue -- upstairs across from the cash registers (behind the Oxxford suits) -- a few racks from Mitchell's (with clothes also from Richards in Greenwich, Marshs in Huntington, and Wilkes Bashford in SF) -- great items from Anna Matuozzo, Kiton, Canali, the new line of Oxxford - including Oxxford slacks, Brioni (including a sick black velvet tux) and others. Not on sale yet, but such a great selection you always have to weigh the question "should I buy now at a decent price, or buy later at a great price but take the risk that it will be gone by then?"
Also when you get off the elevator on the second floor, on a table in front of you there are some high-end neckties (Bizzochi, etc. etc. - obviously from Mitchell's) and just a few pair of shoes from Mitchell's as well, but nothing of note -- just some Tod's and some others but nothing great at all --- so concentrate on the ties and the racks behind the Oxxford Suits (marked by yellow signs with "Mitchell's" on them.)