I rarely read fiction. I'd love to read something great, but I have harder time finding it and getting into it.

Harry Potter and The Methods of Rationality is the best fiction I've ever read, and am actually rereading now, so that's one.

I absolutely love everything written by Alexander Wales, The Martian by Andy Weir, and a lot of stuff from /r/rational. Also I think that Atlas Shrugged and everything written by Ayn Rand is brilliant.

I've read Ready Player One by Ernest Cline, and Mistborn by Brandon Sanderson not so long ago, they were pretty fun, but I wasn't blown away or anything.

Aside from that, I don't know many great ones, so I mostly read non-fiction.