Compete with yourself to accomplish individual musical goals. Competing with others is pointless, unless you're literally competing with someone for a gig.
I think such a competition aimed at the general public would be a fine example of how meaningless most of these "competitions" really are, or "best guitarist" lists or pretty much anything that tries to quantify the subjective.
We're all players here, and we have rather varied musical tastes among us. I assure you, there's no way we could come to a definitive objective answer to "Best" guitarist or any other instrumentalist for that matter. Now leave it up to the general public that we do all pretty much agree doesn't know squat about music? Fun!
What I'm saying (probably too obnoxiously) is that Spud's point about evolving past our competitive nature is applicable not just to musicians but to listeners of music as well. Too much of the way music (or all art really) is discussed involves trying making objective claims about things that are necessarily subjective.