I think that Mythbusters is a great show. The only thing I don't like about it is that it's title is a grave misuse of the word "myth". The word has come to be synonymous with "lie", and I think that this has become so pervasive that it has made it harder to talk about religion - particularly comparative religion, because there is this (false) sense that "myth" and "truth" are mutually exclusive. That isn't how I use the word, and it got me thinking about some other related words that I want to work on defining - defining how I use them at least.
These are all where I am now, not things I'm trying to lay down for all time.
A story is a recounting of events from a particular point of view. Stories are not singular, are infinitely interconnected, and never end - we only stop telling them at one point or another. Stories also come from a storyteller, and are received by an audience. Both of these things change the story with each telling. Apart from storyteller and recipient, there is no story.
"Fiction" is another word sometimes used as a synonym for lie. This belies what every moderately literate person knows - that one can find truths in fiction, perhaps even more readily than in non-fiction. For me, fiction is story which may not conform to consensual reality but which is told with the consent of the audience. What that means is that fiction may not conform to things we generally agree are real - it might have Elves or monsterse or faster-than-light travel, it always has made-up characters, and so on. I use the term consensual reality because what is fiction in one culture might be truth in another. Sorry objectivists - deal with it. So, to put it more simply, fiction is a lie told with our consent.
A myth is a story through which a group of people make meaning. If no one finds it meaningful, then it cannot be a myth. If only one person finds it meaningful, it cannot be a myth. If it is merely an account of widely agreed-upon events, or a recording of some kind, it cannot be a myth. Included in my list of myths are the Bible, Capitalism, American History, the Enuma Elish, Dianetics, Socialism, etc. These are all stories through which people make meaning, and none of them are mere historical records.
How a myth functions is a topic for another post - or ten.
A lie is a story told which does not conform to consensual reality without the consent of the audience. It is presenting what is not meaningful as meaningful, or presenting what is factually false as what is factually true. Lies are about having power over other people while protecting yourself. The storyteller and the audience are not connected by trust, but are instead engaged in combat, though they may not know it.
Facts are a lot more rare than we think they are. A fact is something that every observer would agree upon given full access to any information they need to make the distinction. It is something that, having every question answered, every person interviewed, every measurement taken, every person would agree is true, short of severe mental illness perhaps. Given this, evolution is not a fact. Consciousness is not a fact. The "law" of supply and demand are not facts. Gravity is a fact. The speed of light is a fact.
The concept of "Fact" necessarily ignores philosophical stances which would make all of our experience a dream or an illusion, or which are entirely deterministic. It presupposes that there is a shared material world which we experience, and that we can make decisions which are not fully determined.
Truth is God's truth alone (did I just accidentally reference Calvin? Maybe I did...). Every statement about truth I take to be in part a statement about hope or trust, because it is a limited human being claiming some kind of knowledge which is not limited. Truth is as knowable as God is knowable. Truth-claims are theological, God-claims in the way that I view the world.
Truth is not just something which conforms to someone's presentation of facts, but it is transformative. Truth changes you and makes you better - or it is not truth. You are the test of your truth, and I am the test of my truth.
Gandhi, to theists, would say "God is Truth", and to atheists, he would say "Truth is God". I remember reading that in his autobiography and really liking it.