*only 20th-century books on this list
I could be wrong and yeah, I've read a bunch of nonfiction. Actually reading some 20th-century right now (H.G. Wells) and my favorite book (M.R. James' ghost stories) are mostly, if not all, 20th-century.
Same deal with Sherlock Holmes (if the collection here is 20th-century I've read it for pleasure, too). BTW if you've never gotten into Holmes be sure to read the stories (more so than the novels) high.