What's a Classic?

Today, a friend mentioned to me that she would be using this summer to catch up on her reading of The Classics, and that got me thinking about too things.

1. What exactly makes something a classic?  AND
2. What books would be on my reading list?

According to Mssrs. Merriam and Webster, a classic is defined as, "a work of enduring excellence".  So essentially, any book that is both good and old would be a classic?  Something tells me that it's more complex than that.

At what age can a book join the Classics party?
I'd say that at the minimum a book needs to span more than one generation in order to be considered to have endured.  Since the average length of a generation is about 25 years, I'm going to say that any book on my list must be over 25 years old, so that means only books published before 1986 can be considered.

What determines excellence?  
Now this discussion could undoubtedly go on for hours, but to make things more simple, I'm going to say that in order for a book to be considered to have excellence it must have both universality and complexity.

Universality - It speaks to people over different times and places in history because it reaches towards something truthful within humanity that can be understood beyond its own social or cultural context.

Concrete Evidence of Universality: Movie portrayals, modern rewrites, other media or movements inspired by this writing.

Complexity - Something about the book must be creative, intelligent, or inventive.  It could be the writing style, the subject matter, the theme, the narrative voice, or really anything that shows the authors ingenuity.
Concrete Evidence of Complexity- Varying scholarly interpretation, intellectual debates (presently or at its implementation), the creation of a new genre, dialogue, or topic of study


My List (ever growing, ever changing)
Tess of the D'Urbervilles - Thomas Hardy
Dracula - Bram Stoker (As soon as I get over my fear of vampires.)
I Capture the Castle - Dodie Smith
Gone with the Wind - Margaret Mitchell
A Clockwork Orange - Anthony Burgess (I will try again!)
The House of Seven Gables - Nathaniel Hawthorne (I think he's a genius writer.)
The Illiad - Homer
The Odyssey - Homer
Lord of the Ring Trilogy - JRR Tolkien (I know, I should have read them already.)
Of Mice and Men - John Steinbeck

What books would make your Summer of Classics reading list??