Mahabharata: Myth or Fact?

One of the week ends sitting with TV remote and i moved to Fox History & Entertainment. Mahabharata was going and a question slipped for Vinayak, Is it Myth or Fact? His answer was NO. I was not sure of the reality but it was tough for me to digest. After few mins of discussion, i thought it would be better to Google about it. At the end of day, no one would go through the boring opinions about this topic. I just browsed through few e-pages and my eyes started paining and i end up without any answer. All i could find is different views and evidences on both side. I ll go ahead for some more links later but really i want to know the reality behind this toipc.