So what gets a 42?

I've read it at least 7 times:  Piers Anthony's great fusion of magic, science and supernatural, "On a Pale Horse."  Genre bending,  mixing theology and adventure, there is nothing quite like the story of Zane, the man who became death.   A book you can read over and over and each time find something new about it - or yourself- that gets a 42.  Dune, it goes without saying, is a 42.  Another?  Memory, by Lois Bujold gets the 42,  with her works   A Civil Affair  and Curse of Challion  hot on its heels at 40.