Any D.C. and Philly dining tips?

Lan Zhou, ChinatownIt must be travel season, because I've been getting a lot of requests for tips on places to eat in NYC. I'm going to list a few must-trys for people who like "cheap eats," but I'm seeking some dining tips too! I'll be in Washington D.C. and Philadelphia next week, and I need some foodie suggestions. So if you'e got any ideas, please post a comment. I'm very into food trucks and cart food, and basically anything that isn't already on the most popular list in the local Zagat guide. For NYC, first up is Lan Zhou. I've raved about it before, and I'll rave again. They've got amazing hand-pulled noodle soups, and it's fun watching the guy stretch your noodles at the other end of the restaurant. But it's the fried dumplings that always astound me. You might get other tips about where to get dumplings like these in NYC -- ignore them all, because nothing else comes even close.Xi'an, ChinatownNext up, Xi'an, another place I've raved about before. The address is listed as 88 East Broadway, but this is a standing-room-only shop on Forsyth Street, around the corner. Get a pork burger and a lamb burger, but don't forget about the noodles. I've tried at least eight of the dishes, and they are always astounding. Watch them make your food right before your eyes (like rolling out your noodles by hand), and assume you'll be standing on the street to eat your meal (although there is some seating downstairs in the 88 East Broadway building). Important Update: If you're more of an East Village person, you're in luck -- this weekend Xi'an is opening a new location on St. Mark's just west of 1st Avenue in the space that used to be Seoul Station, and they actually have seats! Num Pang, NYCFinally, Num Pang. Yes, I've raved about this one before too. NYC has a lot of banh mi shops, but I say skip them all and head straight here instead for Num Pang's Cambodian-style sandwiches. The catfish is always a winner, although I think they changed the recipe recently. I suggest going with friends, ordering 2 or 3 varieties, and sharing. And note, there is a small seating area upstairs.So there you have it -- three great tips. Again, if you've got any D.C. and Philly dining tips, please post a comment!