I'd say our local chain for lunch - Clyde's - either in Georgetown or the pretty one at Gallery Place pictured here:or have pizza at my favorite Italian place - Sette -either in Dupont (at Conn. and R. streets) or in Clarendon VA. Sette has wonderful salads, pasta, a great wine menu and AMAZING pizza. I'd recommend a caprese salad and my favorite Proscuitto e rucola pizza with a sparkling rose perhaps? At clydes the turkey burger is really really good!
The hotel monaco downtown, across from the national portrait gallery is a really beautiful hotel in the old restored post office. The restaurant is a great place for brunch as well! If you don't stay there at least check out the great lobby and beautiful courtyard!
In addition to GORE DEAN that was mentioned in the article ( on Cadys Alley here in Georgetown ) which is probably my favorite shop to window shop and dream here in dc
Another store is Random Harvest- 2 blocks north of M street on Wisconsin ave.
They carry a great mix of early 20th century re-upholstered furniture and new furniture of the same style.
That starts about a mile (a little further up Wisconsin Ave.) of some of the greatest design and antique stores in DC such as MARSTON LUCE, DARRELL DEAN, and COTE JARDIN. A great little walk on a saturay morning! Stop in at Cafe Napolean for crepes!
The U street corridor that is mentioned in the article has some interesting shops at more affordable prices but it's hit or miss in my opinion and you have to deal with some scary types of people and the goodies are few and far between ( sorry, just my opinion ) but if you have time definitely check it out!
Of course everyone knows the Smithsonians along the mall - but be sure to check out the famous Peacock Room by J. Whistler which is installed at the Freer Gallery of Art on the nat'l mall which is generally passed over. This is probably my favorite building on the Nat'l Mall -it is very elegant and has a BEAUTIFUL interior courtyard.Also check out the Renwick Galleries which are across the street from the White House on 17th street. This was the first art gallery in the US and is a really great building and frequently has the Smithsonian art treasures on display ( and the BEST gift shop! ).Keep in mind both of these museums are free of admission as they are a part of the Smithsonian! Also -the best time to view the monuments is at night when they are magnificently lit and the amount of tourists is a lot more bearable.
Thats just my 2 cents - the Architectdesign tour of dc :-)