My favorite books: Harry Potter, the Abhorsen Trilogy, His Dark Materials, everything Holly Black, the Gemma Doyle Trilogy, the Inheritance Cycle, the Blue Girl, Drink of Me, Ender's Game, The Forest of Hands and Teeth, Archangel, The Night World books, American Vampire (comic) and many many more. :)
My favourite books - Marty's Shadow, All Quiet on the Western Front, Hamlet, The Story Sisters, Matilda, Trees, The Fence, Life as we know it, Mice, Chinese Cinderella, Skulduggery Pleasant, and... many, many others. Definitely many others.
Harry Potter always has been and always will be my favorite series of all time, closely followed by The Perks of Being a Wallflower, which I just finished rereading a couple of hours ago :) I'm always amazed by how relevant it is to me personally. I gain a new perspective every time I read it. Anyway I also love everything by John Green (which I also need to reread), and I really liked Thirteen Reasons Why. :)
A SONG OF ICE AND FIRE BY GEORGE RR MARTIN (storm of swords is the best one out of them, but they are all great), I also love The Autobiography of Henry VIII and The Memoirs of Cleopatra by Margaret George, The Constant Princess by Phillipa Gregory, Escape by Carolyn Jessop, Beloved by Toni Morrison, The Life and Death of Anne Boleyn by Eric Ives, and so much more but those are my faves!!
Temeraire series by Naomi Novik. Napoleon wars with dragons. All I have to say. :D
Anonymous
Is the favorite books thing still going on? If so, my favorite books are: Harry Potter books (except 5); The Help; Twenty-One Balloons; etc.

mhm :]

Harry Potter, House of Night, Sisters Grim, Percy Jackson, Bras and Broomsticks, anything Edgar Allen Poe, Where the Sidewalk Ends, The Girl Who Could Fly,
Anonymous
Jodi Picoult books. Awesome plots and epic opinion battles. And Harry Potter - for obvious reasons. And a lotta other books that would take next to forever to mention :D
Favorite books right now: the whole of the Sherlock Holmes cannon, the Bible, Unwind, The Name of this Book is Secret series, and The Mysterious Benedict Society.
Harry Potter, duh. Anything by Riordan, and The Wheel of Time, which is the best fantasy series hands down. Also, A Great and Terrible Beauty series by Libba Bray.
Pride and Prejudice, To Kill a Mockingbird, It's Kind of a Funny Story.