I like historical stuff, early 20th century and thereabouts.
My favorite books are George Orwell's novels and essays.
The Spike is a good quick read.
Jack London, who of course wrote Call of the Wild, also wrote
People of the Abyss, about his exploration of homelessness in London. Since he's American it's interesting to see his horrified reactions:
"...the Carpenter, lean and hungry, his grey and ragged overcoat flapping mournfully in the breeze, swung on in a long and tireless stride which reminded me strongly of the plains wolf or coyote. Both kept their eyes upon the pavement as they walked and talked, and every now and then one or the other would stoop and pick something up, never missing the stride the while. I thought it was cigar and cigarette stumps they were collecting, and for some time took no notice. Then I did notice.
From the slimy, spittle-drenched, sidewalk, they were picking up bits of orange peel, apple skin, and grape stems, and, they were eating them...They picked up stray bits of bread the size of peas, apple cores so black and dirty one would not take them to be apple cores, and these things these two men took into their mouths, and chewed them, and swallowed them; and this, between six and seven o’clock in the evening of August 20, year of our Lord 1902, in the heart of the greatest, wealthiest, and most powerful empire the world has ever seen."