OP is looking for a buffet salad bar place-that's what Sweet Tomatoes and Souplantation are. Sweetgreen and Chop't are a bit different, but you can create your own salad there. I much prefer Sweetgreen to Chop't.

Souplantation in CA and Sweet Tomato in FL.

Sweetgreen - locations in G'town and Dupont Circle
Chopt - Union Station

Go online and search for possible other DC locations for these two places.

Is souplantation good? I love salads but remember that place as being gross.

Sweet Greens in Bethesda is pretty good. Not familiar with the places you mentioned.

Where can I find a salad place such as Sweet Tomato or Souplantation in the DC area?