My favorite all time book EVER will always be The Secret Garden
It's a child's book, I know but...I sympathize with Mary so it still speaks to me, even at 34 years old.
And while I am no fan of Anne Rice, the Vampire Chronicles still hold a special place in my heart.
Also: The Brightest Light, Dealing with Dragons, The Hobbit, Harry Potter...there are also a bunch of books I read when I was in Iraq that I forgot the names of that I'm desperate to find, they were all so good~!