I chose fantasy and speculative fiction because it's often scoffed at, and because I love it.
1. The Harry Potter series by J.K. Rowling- Regardless of what sort of books you normally choose, I believe that everyone should read this series at least once. Not only has it sold more books than any other book or series since the Bible, but it is fantastic in so many ways. There are so many good feels here.
For fantasy skeptics:
2. The Chronicles of Narnia by C.S. Lewis- Not only are these great books for adults and children alike, but they are a quick read. If you think that reading speculative fiction and children's (or perhaps middle grade) fiction is beneath you, pick up The Lion, the Witch, and the Wardrobe. Between the writing, the plot, and (if you're looking for a justification for reading a book like this) the allegory, I dare you to walk away from this thinking it was a waste of time.
For real fans of fantasy:
3. The Hobbit by J.R.R. Tolkien- I would love to recommend The Lord of the Rings as well, but despite my deep love for Tolkien, LOTR has some slow parts. The Hobbit, however, has a pace much better suited for the modern reader, and since this is really the springboard for fantasy works, it is an eventual must for every fantasy writer.
4. Wheel of Time series by Robert Jordan- This is one of my favorite series. My sister argues with me about it, but I still think reading this series, or even just the first couple books, gives readers a really good look at fantasy and all of its wonder. It has high fantasy elements, but doesn't stick to elves and dwarves and dragons.
5. The Riftwar Saga by Raymond E. Feist- Another great fantasy book. Feist has great rules about magic, a lot of hidden mysteries, and a style that keeps you reading late into the night.
6. Dragonlance series by Margaret Weis and Tracy Hickman- Most specifically, the autumn, winter, and spring trilogy. I first read this series when I was 11 or 12 (although they were written for adults) and they influenced me for years. Still do. If you are looking for a great fantasy series with all of the beloved elements of high fantasy (elves, dwarves, dragons, sorcery), this is the place to get it.
For young readers:
7. Sweep series by Cate Tiernan- This is a young adult fantasy or paranormal series about a teenage girl who discovers she is descended from witches and has powerful magic. I haven't read it for years, but my memory is that it is one of those YA books that really makes you connect with the main character. And who doesn't secretly wish to one day find that you have hidden powers?
8. Peeps by Scott Westerfeld- Westerfeld is a popular YA author, and I like a lot of his work, but for this list I picked Peeps because a. it is a stand alone novel and I haven't offered that yet, and b. it combines so many cool elements of science fiction (actual science--biology) and fantasy (vampires) in completely new ways
For those considering science fiction:
9. In Her Name series by Michael Hicks- For any fantasy reader who wants to dabble into the world of sci-fi, this series is for you. There are spaceships and wars, but most of the first book takes place in a low-tech world where the primary weapons are swords and daggers. In my mind, it is a great mix of fantasy and sci-fi.
10. Battlefield Earth by L. Ron Hubbard- I avoided this books for years. First it was too "science fiction-y" and then...I don't know. I didn't want to? But when I did--bam! It's a fantastic book. I would almost go so far to say that Battlefield Earth is The Hobbit of science fiction. If you consider yourself a serious sci-fi fan, you can't leave this book unread.
What fantasy, paranormal, sci-fi books would you recommend?