I'd like to nominate The American Senator
by Anthony Trollope. From Wikipedia:
it is notable for its depictions of rural English life and for its many detailed fox hunting scenes. In its anti-heroine, Arabella Trefoil, it presents a scathing but ultimately sympathetic portrayal of a woman who has abandoned virtually all scruples in her quest for a husband. Through the eponymous Senator, Trollope offers comments on the irrational aspects of English life..... Through his often-tactless remarks in conversation, through his letters to a friend in America, and through a lecture in London titled "The Irrationality of Englishmen", he comments on British justice and government, the Church of England, the custom of primogeniture, and other aspects of English life.
Public domain, of course. Available here at MR; if people don't want to convert to ePub it's also available at Manybooks. Free audio at LibriVox.