I highly recommend the Three-Body Problem and its sequel The Dark Forest. Both are rational science fiction in the sense that the plots and character motivations seem internally consistent and follow the book's premises. Much of the book is about the characters (and reader) logically reasoning through what is going on, so I can't describe the plot without giving away spoilers. Although there is no magic in the book, if you enjoyed HPMOR, I would bet that you will like these two books.
I hated Three-Body Problem. I found it incredibly slow and unrewarding (and I never got how ~200 intelligent people in a game called three-body problem somehow don't figure out that the game's about the three-body problem). Partly the dangers of hype, but I really don't think it's very good.
This is the monthly thread for posting media of various types that you've found that you enjoy. Post what you're reading, listening to, watching, and your opinion of it. Post recommendations to blogs. Post whatever media you feel like discussing! To see previous recommendations, check out the older threads.
Rules: