What are you looking for? A lot of places getting great reviews.
Fiola Mare - seafood, DC Waterfront (Georgetown area)
Rose's Luxury - Barracks Row/Capitol Hill. Tons of hype, I don't know anyone that's been disappointed
Kapnos - Greek, 14th St
Del Campo - Chilean or Uruguayan (Penn Quarter)
That's just a handful of newer places I could think up (strangely havent been to any of these yet).
Not so New but Excellent
Mintwood Place - Adams Morgan. Has been on my to do list for ages, can never get a table when I look (at the last minute)
Bar Pilar - My favorite bar. Great cocktails and very good food. warning the plates lean small. Drink and eat upstairs if you can, especially if Brian is behind the bar.
Pearl Dive Oyster Palace - Another favorite of mine. Eat downstairs, the owners are known for their great seafood. Fun crowd
Others - Garrison (new), The Royal (super small, great drinks), Masseria (Ivy City), Sally's Middle Name, Granville Moores (been around a while, great Belgian food and beer), Brasserie Beck, Blue Duck Tavern (West End), Chez Billy (Petworth), Chez Billy Sud (Georgetown), Range (Friendship Heights), Macon Bistrot & Lader (Chevy Chase), Komi, Rasika....
I'd say look up the restaurants on The Washingtonian Magazine website, washingtonpost.com, and Washingtoncitypaper.com and see what grabs your attention.