Breakfast in D.C. or Northern Virginia
These aren't exactly secret places, but they're good:
Ben's Chili Bowl (1213 U st. NW, DC 667-0909) is a favorite ultra-divey breakfast spot. They serve breakfast (or did last time I checked) mon-sat 6-11am, open sun at 12, and late night every other night (2am mon-th, 4 am weekends).
also, florida ave. grill (1100 florida ave NW, DC, 265-1586) used to make a great breakfast