Scott Suchman/For The Washington Post

Time was, D.C. Restaurant Week stood unchallenged on the Washington food calendar, a week of rapid reservation-making and cautiously assembled checklists of dining destinations. Now, it's not even the only specialty food week taking place during the first week of February.

Still, it's one of the most popular weeks of the year to dine out, as restaurants offer prix-fixe lunches for $20.13 and dinners for $35.13. Reservation availability varies, but you'll have better luck (and a better experience) booking lunches instead of dinners when possible. In any case, here are a few participants that are worth a walk-in:

Ambar: Balkan food is new to D.C. so unless you've spent time in southeastern Europe, Capitol Hill's newly-opened Ambar is likely your first exposure to delicacies like kajmak, a fermented cheese popular in the region.

Bandolero: Tableside guacamole had a good run, but it's all about sikil pak -- a tangy pumpkin seed paste that resembles crushed avocados, but has a more earthy flavor -- from here on. Mike Isabella's Mexican restaurant makes a tasty version.

DGS: Who could have predicted that a Jewish-style delicatessen would ever be among D.C.'s most popular restaurants? The double-baked rye bread is a big reason why the sandwiches here make diners kvell.

Urbana: Order a pizza from the Restaurant Week lunch menu and you'll have the newly-installed Anthony Pilla -- one of the most entertaining pizzaiolos in D.C. -- making your pie.

Westend Bistro: Eric Ripert's name isn't on the marquee any longer, but the kitchen hasn't missed a beat under Devin Bozkaya. In fact, the new leadership earned Westend Bistro a spot on Tom Sietsema's list of the D.C. dining scene's best new arrivals for 2012.

Woodward Table: Jeff Buben carries forth the best of Vidalia at his newest downtown restaurant while also pushing boundaries: see chef Joe Harran's braised lamb shank, served with dates, celery root puree and a dollop of a blood orange gastrique.