Rens Ramen in Wheaton is the most authentic to me (studied abroad in japan). I don't actually care for much of the ramen IN DC, Daikaya did not impress me but I only went when it first opened. I prefer Akira in Rockville or Stamina in Bethesda to it, but again Rens is the best imo. Oh actually they opened an Akira in Adam's Moegan so I would recommend that!