Lord of the Rings is my favorite and probably always will be. It's just such a good story, and so classic and eternal. The books are, for the most part, better than the movies (Faramir, anyone?!) but I still love both.
The Wingfeather Saga by Andrew Peterson is a precious story about the powers of family, love and the arts. It's so good. I can't recommend these books enough.
I can't fit the covers of all the Lunar Chronicles on here, but they're really amazing. I love fairy tale retellings with all my heart, and these are particularly good - so creative! So well-written!
You probably haven't heard of these. The Five Stones Trilogy is written by a local Maine author, and I devoured them, waiting impatiently on the edge of my seat for the third installment. They're so good - the worldbuilding is lush, the characters are well-developed, the plot is perfect- so I would recommend them to any fantasy reader.
Of these, Moonblood is the best, but they're all worth a read :) Heartless is an excellent allegory about our Savior and the lengths he will go to get us back. Veiled Rose is a story about true beauty, and Moonblood is just plain epic. Starflower is a beautiful prequel that provides quite a bit of beautiful backstory and insights into beloved characters. I haven't read the others yet, although I do own them, but believe me when I say that I will very soon!
There's more, of course, but I'll add those later :) For now, if you haven't read any of the ones I have on here, you must. Now. *aggressively shoves books at you*