Tried to go the the Market Cafe this Saturday (9th and 37th?), but they're closed on Saturday, so found myself at Mitchell London Foods, a few blocks north, a small storefront with a few tables and a counter (I think it's an outpost of a catering place). Had a really, really good bowl of chicken soup, great flavored broth with some nice chunks of chicken and pieces of onion. Came with two pieces of thick-sliced lightly grilled white bread. Cost $4 and I was full for quite a while. Took home a tasty yellow cupcake thickly covered with chocolate frosting.
Other people were eating the bottomless stack of pancakes, which came out fresh every few minutes, small and well browned, with a little pitcher of syrup.
Back on the soup front, the Ukranian thread mentions Teresa's on 1st and 7th. I've had good white borscht and mushroom barley there. Also, there's a new diner up by Columbia, Deluxe, where I had a very good cream of spinach soup.