Here's the ones I have read:
To Kill a Mockingbird - I read it first in 7th grade and again several times as an adult. If you haven't read it again, do it now.
Anne Frank: The Diary of a Young Girl - I read it in 5th or 6th grade, need to reread it again
1984 - I think 11th grade. It's scary how much of this became true.
Charlotte's Web - I've read it more times than I can count. My favorite childhood book; neither of my kids were interested in reading it.
Gone with the Wind - Just as good as the movie
Animal Farm - read it either before or after 1984....4 legs good, 2 legs bad!
The Catcher in the Rye - freshman year of college...I read every depressing coming of age book in existence. This is the top of the heap.
The Help - Really? Hardly a classic. I read this for book club. It's okay, but it didn't rock my world, except for I still want to make a caramel cake.
The Grapes of Wrath - like many people, I was forced to read it in high school, but was glad I did.
Hamlet - doesn't everyone have to read this in high school? I went on a major Shakespeare binge after reading it and also took Shakespeare in college.
Of Mice and Men - another forced read in high school, I thought it was great and I finally got the Bugs Bunny cartoon based on the characters.
The Secret Garden - Loved, loved, loved this book as a girl!
Romeo and Juliet - see other comments about W.S.
The Handmaid's Tale - another depressing book about the future....I read it when I was a senior in high school, pretty much coincidentally with.....Brave New World
Wuthering Heights - too bad high school kids don't read this one any more like I had to...It's creepy!
Macbeth - considering my Shakespeare fetish, you would think I'd have loved the movie "Shakespeare in Love". I did not.
The Fault in Our Stars - a modern book, destined to be a classic. I loved it.
In Cold Blood - I couldn't put it down when I read it. Fascinating!
Charlie and the Chocolate Factory - my 2nd favorite book as a kid, next to Charlotte's Web. Pure genius.
The Scarlet Letter - I forced read in high school, now kids don't read it. How will they catch the reference when people say "the scarlet letter"?
Water for Elephants - a ladies book club favorite; it's better than "The Help"
The Raven - glad a poem made the list
The Time Traveler's Wife - I don't really like fantasy books, this one included
The Odyssey - high school again! I haven't read it since but have seen "O Brother, Where Art Thou?" a million times
The Immortal Life of Henrietta Lacks - well written and very interesting
The Glass Castle: A Memoir - Excellent book! Surprised to see it here.
Beloved - a book club read....I highly recommend it.