A few words about one of my favorites (largely because it's close to home) - Bamboo Buffet, in Bailey's Crossroads (Fals Church).
Buffet only, serving 500+ meals per day and getting really good notes from the health inspector (hate to put that at the top, but it seemed to fit) - $6.99 at lunch, about $7.99 dinner $10.99 weekends or thereabouts, basic beverages included. Diners include locals and a large percentage of Asians, service (both mgt and waitstaff) are very friendly.
It's a zoo at lunch and a really BIG zoo at dinner, completely indescribable weekends, but the food is hot, fresh and plentiful - however, the selections change a little over time reflecting (I believe) food cost ups and downs. No more yummy dimsum-style rice noodles with shrimp, or beef ribs, for instance.
This is a Chinese buffet with a workable selection of non-Asian choices - fresh rolls, not-so-good pizza (nobody eats it), VERY good simply-cooked salmon fillet, fried fish and a few other things.
Very popular made-to-order pho at all times, hot-pot available for a slight upcharge, Peking Duck advertised (I don't dare brave the crowds with my cane or walker except at lunch), Chinese "crullers" and soy milk a rarely-seen treat. Modest selection of sushi made in plain sight constantly - nothing too fancy, heavy on the avocado and salmon (but that's what I like best) and quite flavorful. Mussels are large and moist and well-flavored, plenty of in-shell prawns even at lunch, more seafood at dinner & wkends.
Dumplings and the like are a weakness - usually either dull & dry, or "mystery" and dry, not much variety but that's like the Woody Allen joke about the little old lady complaining "I didn't think the food was very good ... and such small portions!" - you will find good food here, but you have to select the best from among the ordinary.
I never get as far as the salad/dessert area, never get much past the sushi - why? Because if I'm in the mood for something that is very workmanlike but doesn't have to be REAL special, and I really need a sushi-feed, you could do a lot worse for the price.
Next time I'll give a word about Dragon Sea Buffet in Springfield - a good step up in quality. Still getting over the closing of Appetizer Plus in Rosslyn - my sushi addiction has never been the same since it left us.