For books written during or in the vicinity of our lifetimes, especially the non-serial.
Sort of amazed this wasn't a thread yet given how many threads for specific books/authors there are.
It came to mind to make one because today I went down to the library and swallowed Maxwell's Demon by Steven Hall whole. First time I've gone cover-to-cover completely uninterrupted in years. I don't know if I'd call it good just yet, still stewing on it, but it was a lot of fun.
edit: oh wait it's right there im a moron how did i miss that three times