I take it most on here have a few novelists who they felt compelled to read their complete works? Who are they and why? Do you tend to go through an author's work all at once, or do you just happen to cover that territory over the years? It probably depends on the author.
In my case, I have not done that with any classic, non science fiction authors, but I have a curious aspiration to get acquainted with the complete or near complete novels of two classic novelists, who are a little off the beaten path in this day and age. These are William Makepeace Thackeray and Sinclair Lewis. I read Henry Esmond by Thackeray, and Babbit and Our Mr. Wren by Lewis, and enjoyed all three very much. So, I am making it my project to get to know these authors really well. I felt that they are both often satirical, but Thackeray gives you much content to chew on with a delivery that requires the same effort, and Lewis has probably far less depth but very pithy humor. They both are curiously flawed in some ways, and very opinionated and sharp in others, and both give you a tremendous feel for the times they hail from, or in Thackeray's case sometimes, what he chose to focus on of the 18th century. I also feel they are both curiously neglected these days.
I have only done this with one author in the past, and that is Isaac Asimov. Granted, I didn't read his children's novels or the Fantastic Voyage II, but I think I'll pass on those. I devoured every lengthy work of fiction that man wrote as a teenager. I love knowing him so well, and so I'm finding some new idols to add to my unusual prospective pantheon. Walter Scott is also of interest, because Asimov is a master of science fiction, but I also enjoy the historical novel, and enjoyed the short story "The Two Drovers" by Scott, and think it would be an interesting balance to know a true master of historical fiction.
I'm also working my way through a variety of classics, trying to add some general breadth all the while gaining depth in these authors of choice.