Number 1 of course is Cryptonomicon by Neal Stephenson

Stephenson’s 1999 novel features World War II code-breakers and 1997 geeks in a complex, interlocking storyline.

“It’s so long, and so dense. It’s almost 1000 pages long, and those are big pages. It must be half a million words long,” says Charles Yu, author of the story collection Sorry Please Thank You: Stories.

He adds, “So much information. It’s a fact: a copy of Cryptonomicon has more information per unit volume than any other object in this universe. Any place that a copy of the book exists is, at that moment, the most information-rich region of space-time in the universe. If you drop a carton of Cryptonomicon paperbacks into a black hole of any size, the black hole doubles in size. 

It’s true, I asked Stephen Hawking. 

You get my drift. It’s the infodump of all infodumps, and I mean that as a very high form of praise, because it’s great info, and the dumping is done so well. It’s so damn entertaining! Everyone praises it and loves it — and yet, I don’t hear all that much about it. Maybe I travel in the wrong circles. It’s just one of those books that you could put on your Before I Die reading list, and then it’ll be there on the day you die, and you’ll be like, “oh, shoot, forgot to read all those awesome books.” Don’t let that happen to you! Read this book! Your brain will swell with information. A person who has recently read Cryptonomicon is temporarily the smartest person on Earth. That’s a fact.”

Number 2 is Dune by Frank Herbert

The classic novel about a desert planet and the power of the Spice Melange.

It’s hard to believe that people haven’t actually read this book — but Pat Cadigan, author of Synners, Dervish is Digital and many other books, says she believes a lot of people “probably think they’ve had the Dune experience from either the movie or the Syfy miniseries.” Also, a lot of people probably “read around” Dune, reading the prequels and the sequels, but never actually dive into the original book. “It’s not an easy read,” says Cadigan, because it’s both dense and complex. But if you’ve only read the other books or seen the adaptations of this masterwork, you haven’t had the proper Dune experience. This is a “full-immersion experience that has to be read to be fully appreciated,” says Cadigan.

This post was one of the top 100 io9 posts of 2015:

http://io9.gizmodo.com/the-100-most-popular-io9-posts-of-2015-1750126944