The interesting expressionist atmosphere and, most of all, a memorable performance by Greta Garbo (does she give any other kind?) both make "The Joyless Street" worthwhile. G.W. Pabst's style also makes a good combination with the setting in post-World War I Vienna. The supporting cast is also good, and all of this makes up for the lack of a first-class story.
Garbo is well-cast as the daughter who is the only real hope of an impoverished family trying to survive in a cold, unforgiving postwar city that is ruled by a handful of predatory exploiters. Just her eyes alone communicate volumes, and her character transcends the rest of the material. Pabst wisely included plenty of close-ups of Garbo, and these leave a lasting impression of her character's weary perseverance and strength of character.
Several of the other characters also have interesting stories of their own. There seem to be a number of different versions of the feature, with widely varying lengths, and thus with the story differently edited, so that some versions will work better than others. But regardless of the story, the setting is effectively rendered, and Garbo's performance stands out.