What Makes A Classic A Classic?

I started reading A Whisper in the Dark by Linda Castillo tonight, and in the first chapter, the heroine gets a shipment of books. She pulls out some classics and actually gets teary-eyed over them (sound familiar, anyone?) and it made me start thinking...what makes a classic a classic?

Dance Chica from Insomnomania is hosting a Classics Book Club. But why did she choose the ones she did? What separates Pride and Prejudice from Lover Awakened? Do they have to be old? Written in a flowery style?

Would Dean Koontz or Stephen King be considered classic authors? Why is Hemingway at the top of the list? What makes The Portrait of Dorian Grey a classic?

I'll be honest and tell you that I've always been a sucker for the classics. The first time I got sucked into a Dickens novel I was a goner. I try to read a classic at least once a month, and I can't wait to share them with my children when they get a bit older. Already I've started reading them some of my favorites from childhood: Anne of Green Gables, Oliver Twist, The Wind in the Willows.

But why do we consider these classics? I went to Ask.com and typed in "What makes a classic novel a classic" and got tons of related links, but none that really defined our exact criteria for what makes a classic stand-out above all others. Some sites said it was a book written before the 20th century, some said books that are on classic literature lists with universities, others said literature was labeled "classic" by the accolades it received.

At Turn Another Page, Valeen and Jennifer have been hosting a Remember the Classics book discussion for romance novels. Where did they get their list of titles from? What makes The Bride by Julie Garwood a classic? Judging by the standards I read about all over the internet, a classic is old, right? True, JG started publishing novels more than a few years ago, but I'm sure she'd take offense if we said her writing was "old".

So tell me, what makes a classic 'classic'? How about in the romance community. When someone says "Classic romance novel" what do you think of? Why? Because they were pioneers for the genre?

What about contemporary authors? Do you think 30 years from now J.R. Ward or Sherrilyn Kenyon will be considered classic authors? Why or why not? What other authors do you think WILL...or won't?

Enlighten me.