Oh this is hard, as I love many novels and have quite a collection of them myself, but I know what my number 1 is.
Here's my list:
1.) George Orwell, 1984
2.) John Steinbeck, Grapes of Wrath
3.) Charles Dickens, Great Expectations
4.) Joseph Heller, Catch-22
5.) J.D Salinger, The Catcher in the Rye
6.) Cervantes De, Don Quixote
7.) Anthony Brgess, Clockwork Orange
8.) J.R.Tolkien, Lord of The Rings: The Fellowship of The Ring
9.) F. Scott Fitzgerald, The Great Gatsby
10.) J. K. Rowling, Harry Potter and The Goblet of Fire
This was VERY hard to do since I've left out other favourites like The Voyage of The Dawn Tredder (The 3rd Narnia book), Of Mice and Men (I'm looking at you Skumfrog ), The Hobbit and many others, but whatever, right now though, thats my top 10, and it could change at an instant by replacing one of the ones I missed to one I listed now, but one thing that will never change, unless the final Harry Potter book amazes me to no end, which it will but not to the magnitude the way 1984, my number 1 and it seems forevever will be hit me.