I've worked in libraries for years including a few in Texas, so it is a wonder that I've never read a western. Part of the problem then with reading your first book in a genre is that you lack the language to properly describe it or make comparisons. Now I wonder if I shall ever read another for the fear that the next one won't hold up to The Sisters Brothers by Patrick deWitt.
It is the gold rush years and the infamous Charlie and Eli Sisters are riding from Oregon City to San Francisco on orders from the Commodore to kill Hermann Kermit Warm. There is trouble with horses, whores, a red bear pelt, excessive brandy drinking, a man named Mayfield, a witch and a mysterious magical formula. Large sums of money come and go. The characters are unique, but without a lot of overall development. Is this usual for a western? Is the level of violence similar to other westerns? Is this a parody of the genre, a homage or both?