What book do you wish more people knew about?

The Cradle series by Will Wight, it's a wonderfully fun, light and long (12 books) fantasy series that reads a bit like a shounen anime. Sure, it might not be for anyone, it is maybe not a high literary achievement for an experienced fantasy reader, but it could be an excellent entry-drug or even a nice break from heavier reading!
- It might not be for anyone, but each book is a super-quick read, so I'd strongly recommend at least trying Unsouled if you are at all interested. If you don't like it, you can stop. If you do, you probably can't.

Texasville by Larry McMurtry. People know about (and hopefully love) Lonesome Dove and Last Picture Show. Texasville should be recognized alongside those as one of his best works. It's one of the funniest novels I've read.
He is the master of creating characters that are both satirical but you love so much.

Johannes Cabal the Necromancer (the whole series, really) by Jonathan L. Howard. Hilarious, engaging, satirical dark comedy mixed with fantasy, pure excellence from the dude who wrote the Broken Sword games. One of my favorite series, hands down.

James Michener. His works are amazing but a lot will probably be put off by the shear size of the books. Hawaii is one of my all time favorite books.

Three men in a boat by Jerome K.Jerome
- And as a follow-up, To Say Nothing of the Dog by Connie Willis. I have The Men in a Boat, but I'm waiting for the perfect time... Which will be in the next week or two

The Licanius Trilogy - there are some heavy cliches, especially with the 'fantasy needs weird names' trope, but also some very good novel ideas, and the overall plot ties together very nicely